Website hacking — the act of exploiting weaknesses to gain unauthorized access to a website, database, cPanel, or admin dashboard — is a reality that some webmasters struggle with. In the hands of bad actors, automated hack tools and exploit kits make it especially easy for hackers to gain access to a plethora of information, including passwords and credit card details.
Not all hackers use their abilities for harm, however. Some turn their expertise towards safeguarding sensitive data and infrastructure. These “Ethical Hackers” or “White Hat Hackers” employ their knowledge to protect against potential threats (instead of orchestrating them).
Nevertheless, the ugly truth remains: there are individuals who exploit their technical skills for nefarious reasons, driven by greed, revenge, or sometimes just for amusement.
The best defense? Understand the common hacking techniques they use and take a defensive stance to help protect against and prevent a compromise in your environment. In this post, we’ll cover the most common website hacking techniques — arming you with knowledge to protect your site from hackers and malware.
Contents:
Common Website Hacking Techniques
While website owners often implement security measures, overlooked vulnerabilities can leave them open to a hack — underscoring the importance of hardening your website and patching your website software against attackers. So, let’s take a look at the most common hacking techniques used by attackers.
1. Phishing & Social Engineering
Phishing is an attack that occurs when bad actors disguise themselves as trustworthy entities, luring victims into revealing sensitive information. Targets of phishing and social engineering techniques can range from individuals to large corporations, with attackers seeking login credentials, credit card numbers, or other personal data.
One of the most familiar phishing techniques is deceptive phishing, where hackers impersonate legitimate companies, duping victims into handing over their data. Link manipulation is another common method where attackers mask malicious URLs, making them appear as though they belong to authentic websites. Then there’s pharming, redirecting a legitimate website’s traffic to a fake alternative. Attackers are also using advanced technologies like AI to enhance phishing campaigns by crafting more persuasive and personalized messages.
Some common characteristics of a phishing attack include peculiar or urgent requests from familiar companies or individuals, or convincingly designed login pages. For example, we’ve seen fake WordPress database upgrade notifications aimed at harvesting user credentials for unauthorized access to systems.
2. Cross-Site Scripting (XSS) Attacks
Cross-site scripting (XSS) is a dangerous vulnerability frequently found in web applications. It allows attackers to inject malicious scripts into web pages viewed by others, enabling bad actors to attack unsuspecting visitors or steal their sensitive data.
XSS attacks can be categorized into a number of different forms, including:
- Stored XSS: where the injected malicious script is stored on target servers in places like databases or comment fields, which then becomes harmful when the victim retrieves the stored information.
- Reflected XSS: where the malicious script is mirrored off the web server in responses like error messages or search results and delivered to the victim through a medium like an email or malicious link; the harmful code is then executed when it is reflected back to the user’s browser from the “trusted” server.
- Blind XSS: where the hacker’s malicious payload is saved on the server via front-end forms and triggers when accessed by the backend user or admin.
- DOM-Based XSS: where the attack payload is executed by modifying the DOM “environment” in the victim’s browser.
Common indicators of an XSS attack include unpredicted activities on a site, such as pop-ups or unexpected content changes. For instance, attackers can hijack a WordPress admin session to create rogue users or install a malicious plugin.
To mitigate XSS attacks, user inputs need to be effectively sanitized to prevent intrusive scripts from rendering onto web pages. This could involve using allowlist values, managing HTML in inputs, sanitizing values, using HTTPOnly flags on cookies, and employing a web application firewall (WAF) for added protection against attacks.
3. SQL Injection Attacks
SQL injection (SQLi) is an attack targeting web applications and websites that use SQL databases. Attackers inject malicious SQL code through input fields on a website, providing them unauthorized access to sensitive data like customer records, intellectual property, or other sensitive personal data.
Attackers use various methods for SQL injections. They might manipulate web page input to alter and execute commands on the database server or exploit database errors to obtain confidential information. SQLi attacks typically occur via web page or application input such as search boxes, form fields, or URL parameters.
Common types of SQL injection techniques include:
- Union-based SQL Injection: This common method extracts data by extending the original query results with the UNION SQL operator.
- Blind SQL Injection: Attackers pose true or false questions to a database to decipher information based on the application’s response.
- Boolean-based SQL Injection: Attackers manipulate database responses using Boolean operators, enabling them to deduce whether their malicious input returned true or false, even when no explicit data is returned.
- Error-based SQL Injection: Used when error messages return full query results to reveal confidential database information.
- Time-based SQL Injection: The attacker delivers SQL queries that prompt the database to delay its response, thereby using the response time to determine whether the query outcome is true or false.
To protect against SQL injection attacks, you’ll want to keep your website software patched with the latest updates or use a web application firewall to mitigate risk.
4. DDoS Attacks
Distributed Denial of Service (DDoS) attacks primarily aim to disrupt the regular functioning of web services or applications. The attack overwhelms targeted servers, networks, or services with a surge of internet traffic, causing outages or substantially slowing down the website and service.
DDoS attacks cover a spectrum of tactics, exploiting various aspects of a network connection. Usually, they leverage multiple compromised devices to orchestrate a coordinated, massive traffic flood.
Some common types of DDoS attacks include:
- Volume-Based Attacks: These attacks overwhelm a system’s bandwidth with massive data volumes, causing network congestion. Common kinds include ICMP, UDP floods, and other spoofed-packet floods.
- Protocol Attacks: These focus on exploiting vulnerabilities in server protocols to consume server resources, thereby causing a denial of service. Examples include SYN floods, fragmented packet attacks, and Ping of Death.
- Application-Layer Attacks: These attacks target specific application layers, mimicking genuine requests to overwhelm the server. They are harder to detect due to their seeming authenticity.
Symptoms of a DDoS attack may include a sudden surge of requests to a specific endpoint, unusual traffic spikes, difficulty accessing your website, slow loading files, unresponsive servers, traffic overload from a single device type, geolocation or browser version, or internal server errors — all of which require immediate investigation.
Blocking attacks require a multi-layer approach. Network monitoring and traffic analysis can help identify unusual spikes that may signal a DDoS attack. Employing rate limiting, IP filtering, or geo-blocking can also help block suspicious traffic and mitigate DDoS.
5. Plugin & Theme Vulnerability Exploits
Plugins and themes are incredibly powerful components that can offer a wide range of benefits to your CMS. However, if a vulnerability or bug is present in the software that causes a security loophole, hackers may exploit these defects to infect your site or gain unauthorized control over your environment.
Attackers capitalize on these security loopholes to launch a variety of attacks ranging from unauthorized access to defacing websites, injecting malicious scripts, or even taking control of the entire server.
Nulled plugins and themes — pirated versions of premium components — provide another avenue for exploit, as attackers often embed malicious code and backdoors in the pirated software. Oversights in setting restrictions or defining roles can also potentially provide users more access than necessary, giving a gateway to exploit insecure permissions.
Automated hack tools make it even easier for hackers to identify and target websites with outdated software, underscoring the importance of regular software updates to help mitigate risk. And be sure to avoid installing nulled plugins or themes to help protect against malware and website backdoors.
6. Brute Force Attacks
Unlike a lot of the other techniques listed in this post, brute force attacks don’t rely on software vulnerabilities within your website’s environment. Instead, brute force relies on weak credentials and poor password security to gain unauthorized access to a website or account.
Brute force attacks primarily target login credentials of websites, emails, servers, or any secure network requiring password authentication.
Some common types of brute force include:
- Simple brute force attack: Attackers try all possible password combinations. This method is time-consuming and uses significant computational resources.
- Dictionary attack: With the help of common base terms from dictionaries, attackers sequentially attempt variations of these base terms, thereby increasing the success rate by exploiting the balance between users’ tendency to use common words and the need to meet password complexity requirements.
- Hybrid brute force attack: This method combines the dictionary attack alongside brute force techniques to guess more complex passwords. Having definitive information like the number of characters or other details about the makeup of a password can greatly speed up a hybrid attack.
- Credential stuffing: This attack leverages usernames and passwords leaked from data breaches to attempt login. This highlights the importance of updating your username and password if your data has been involved in a cybersecurity breach.
Brute force relies on weak passwords. A strong password combined with limiting unsuccessful login attempts and multi-factor authentication will make it much harder for attackers to guess your website credentials.
7. Code Injection Attacks
Code Injection, also referred to as Remote Code Execution, involves embedding harmful code into scripts or executable files. Hackers first locate attack surfaces in an application, such as file uploads, form fields, or cookies, that accept untrusted data for executing codes. This vulnerability can be used as a backdoor as the infiltrated code can help attackers upload and modify files, create or delete CMS users, and even launch full featured web shells.
Code injection attacks usually stem from poor quality of code in the web application. To mitigate risks, website developers should adhere to the recommended guidelines for developing secure applications. Webmasters who use third-party software for their websites should keep it fully patched. A good website firewall can also help block malicious requests trying to inject unwanted code into web applications.
8. DNS Spoofing
DNS Spoofing, also referred to as DNS Cache Poisoning, is an attack technique where DNS records are manipulated to redirect users to a deceptive, malicious website that mirrors the user’s anticipated destination. Upon landing on the fake site, users may unknowingly log into what they believe to be legitimate accounts, thus providing the attackers with access to credentials and sensitive information. Furthermore, the deceptive website could download and install worms or viruses on the user’s device, granting the attacker ongoing access to user data and devices.
This mode of attack exploits DNS and its associated vulnerabilities. The methodology can vary; attackers may manipulate the address resolution protocol (ARP) to access router traffic and alter domain name resolution records, modify the DNS server’s records to divert traffic to the malicious site, or manipulate an intermediate name server’s caching system to orchestrate a Man-in-the-Middle (MITM) attack.
Repercussions of DNS Spoofing can be severe, from stealing sensitive user data to gaining sustained access to users’ devices — and in rarer cases, resulting in ransomware. Additionally, by rerouting traffic from valid sites to an attackers’ rogue third party-site, hackers can boost their site’s authority and search ranking, thereby drawing more traffic to the malicious domain in the future.
9. Cookie Theft
Cookie theft, a threat to website owners and users alike, involves hackers stealing cookies from users’ computers to access personal data or login information. Cookies help websites remember users and customize experiences. However, if exploited by bad actors, they can be used to hijack user sessions, leading to unauthorized site access — a common method of session hijacking.
Cookie theft can originate from several sources, including:
- Web based: Personal cookies can be stolen when malicious code is injected into a website and executed in the user’s browser, as seen with XSS attacks.
- Client side: Cookies may be stolen from the browser by malware on the local computer.
- Man-in-the-middle (MITM) attacks: Attackers intercept communication between the user’s browser and the site to steal cookies or sensitive information.
Despite cookies being the safest way to store session data on the user’s end, they require proper protection as WordPress utilizes cookies to maintain user logins. You can help prevent cookie theft with proper website hardening and security measures such as secure SSL encryption for your site, website firewall, and keeping your computer free of malware.
10. Clickjacking
Clickjacking, also known as a UI redress attack, Is a technique that tricks users into clicking links or buttons that perform unexpected functions. This can involve overlaying a deceptive layer over a legitimate website, misleading users to interact with hidden elements unknowingly.
Some common clickjacking methods include:
- Invisible iframes: Involves layering an invisible iframe to bait users into clicking on malicious content.
- Pointer events: Floating div tags cover target UI elements to trick clicks onto underlying iframes.
- Transparent overlays: Transparent frames are layered over site buttons or links, hijacking unsuspecting users’ clicks.
Any action that involves a single click on your site could in theory be susceptible to clickjacking. However, you can mitigate risk by adding X-Frame-Options headers to your site, setting up a content security policy, and using a web application firewall.
11. Man-in-the-Middle Attacks
A man in the middle (MITM) attack occurs when a perpetrator intercepts communication between a user and an application to steal personal information like login credentials or credit card numbers.
E-commerce sites are often the targets of MITM attacks, with stolen information being used for identity theft, fund transfers, or advanced persistent threat (APT) assaults. MITM attacks are comparable to a mailman stealing account information from your sealed bank statement.
The execution of an MITM attack involves two stages: interception and decryption.
Interception can occur passively, through the creation of malicious WiFi hotspots, or actively, by employing techniques like IP spoofing, ARP spoofing, or DNS spoofing. These methods misdirect user data travel, channeling it through the attacker’s network instead.
After interception, the attacker then needs to decrypt any SSL traffic. This could involve HTTPS spoofing, SSL BEAST which targets a TLS version 1.0 vulnerability, SSL hijacking, or SSL stripping, each one designed to intercept, control, decrypt and reveal user session data.
Steps to protect your site from hackers
By knowing how hackers operate, you can better protect your site against attacks. Let’s review some basic steps to protect your website and server environments against a hack:
- Regularly patch and update your website software. Ensure all your website software, core CMS, plugins, and themes are up-to-date. Hackers often exploit known vulnerabilities in outdated software.
- Maintain strong passwords for every account. Use strong, complex passwords and ensure that credentials are unique to prevent lateral movement and credential stuffing attacks.
- Limit login attempts on your admin panels and login pages. This will help to prevent brute force attacks against your accounts.
- Set up SSL certificates on your site. Always use secure, encrypted connections (HTTPS) for all operations.
- Set a regular website backup schedule. Regularly backing up your website will make it easier to recover from a compromise or issue with your site.
- Implement two-factor authentication. Multi-factor authentication adds an extra layer of security to prevent unauthorized access to your accounts.
- Monitor website and server traffic. Regularly monitoring your traffic can help quickly identify any unusual spikes that could indicate a DDoS attack or indicators of compromise.
- Scan your website and server for malware. Regularly scan your website environment for malicious code and unusual activity. Respond quickly to threats that arise.
- Use secure and reliable DNS servers. Regularly monitoring your DNS records can help you catch any unauthorized changes early.
- Restrict file uploads to your website. Limit and secure file uploads, as they can be a pathway for hackers to introduce malicious scripts.
- Set up a Content Security Policy (CSP). A CSP can help prevent cross-site scripting and clickjacking attacks.
- Get a website firewall. Use a web application firewall (WAF) to help patch against known software vulnerabilities and filter out malicious traffic before it reaches your website and server.
Looking for a hand preventing hacks and cleaning up? Our team is available 24/7 and loves to chat about website security!
Justin Channell
Josh Hammer
Victor Santoyo![Malware comes in many different varieties. Analyst Krasimir Konov is on this month’s Sucuri Sit-Down to help keep them all straight. From malicious iframes to SEO spam, join host Justin Channell as he racks Krasimir’s brain on all the different types of malware. Also, Krasimir discusses his recent blog post about a malicious cURL downloader, and Justin breaks down the latest website security news, including patched plugins you should update. Podcast Transcript Justin Channell: Hello, and welcome to the Sucuri Sit Down. I'm your host, Justin Channell, and this is a monthly podcast about website security, where we get in-depth with the malware removal experts here at Sucuri. Later in the show, I'll have our analyst Krasimir Konov to chat about some different types of malware, but first, let's take a look at other topics we've published on our blog and Sucuri labs notes this month. First up, we have some new information about credit card skimming with hackers using a hybrid method to steal payment information from eCommerce websites. Our analyst Dennis Sinegubko wrote about this for the Sucuri blog back at the beginning of June. Now, most credit card stealing malware is a client side JavaScript that grabs data and sends it to a third party server. But, that approach has a drawback for bad actors because it's still possible to track the requests and catch them as being suspicious. Now, to get around that, bad actors have started harvesting information server side by modifying core PHP files. In this case, the infection would be undetectable from the outside, but it's still going to be pretty easy to find because you're rarely modifying any of those core files, so any of those changes that are going to come up are going to be suspicious. To get around both of these drawbacks, we're seeing bad actors combine the two. So client side snippets of JavaScript are sending stolen credit card data to server side scripts that they've installed on the same server as the site. Now, this allows bad actors to cover their tracks a little bit because the traffic that's being redirected is going to the same server, and that's less likely to be flagged as suspicious. It's a bit more complicated to pull this off, but our team has been seeing this hybrid approach in the wild, so it's something to be on the lookout for. Now, another month has passed, and we found more cross site scripting attacks targeting WordPress plugins. Most notably, we discovered one that affects users of the YITH WooCommerce Ajax Product Filter plugin. Now, this is a plugin that allows WooCommerce stores to be filtered by product type, and it's pretty popular. It's got about 100,000 users right now, so with it being vulnerable, it's very important that all of them update to the latest version, which is 3.11.1. Some of the other plugins we found cross site scripting vulnerabilities with included Elementor Page Builder, Careerfy, JobSearch, and Newspaper. If you're looking for a full list of vulnerabilities that have been patched this month, John Castro at the Sucuri Labs blog has you covered. Check out our show notes for the link. Also, this month I had a blog go up detailing what's called a jibberish hack. It's basically the same motivation as an SEO spam attack where bad actors use your site's good standing to redirect visitors to their own sites. But in this attack, you'll find a bunch of randomly named folders filled with a ton of HTML files with really nonsensical file names like cheap-cool-hairstyles-photos.html. It's just going to be a mishmash of keywords that clearly you didn't put there. Unfortunately, just deleting all those HTML files and folders is not going to be enough to get rid of that jibberish hack though. You're going to need to fully clean any hacked files and database tables, and then you're going to have to deal with all the damage caused to your site's standing. And just keep in mind, if you find anything about that process too daunting, we're always here to help. Now, for this month's Sit Down, we have Sucuri analyst Krasimir Konov. Earlier in June, he had written a lab's note about a malicious downloader script that used the curl function, and we chatted a bit about it, but more importantly, we went really in-depth on all the different varieties of malware that website owners need to be aware of. But, before I get started with Krasimir, I just wanted to remind you about the Sucuri Sync-Up, our sister podcast. It's a weekly website security news briefing that you can find anywhere you get your podcasts, as well as the video version on our social media feed, and now you can even get it on your Amazon Alexa smart speakers. Just search Amazon skills for Sucuri Sync-Up, add the flash briefing, and get new content delivered every Monday. Now, on with the show. Hi Krasimir, thanks for joining us on the show. I thought we could start off and maybe have you tell us a little bit about yourself and what you do here at Sucuri? Krasimir Konov: Yeah, sure. Well, I joined Sucuri originally in 2014, but I've been in the IT business for about 10 years. Nine of those I did security. And currently at Sucuri I'm one of the malware analysts. I used to work in the front lines, used to clean websites and whatnot, and then I gradually moved up, and now I'm working in the malware research department. And my day to day job is basically analyzing malware, and then once I analyze it and figure out what it is, then I will create a signature for it. And we'll add those signatures to our tools, so we can automate some of the work we do. And I also write some Labs Notes blog posts. Usually, if I find something interesting in malware or some security topic, I'll write about it. Justin Channell: Yeah. And of those topics recently that you wrote about, one was about a malicious curl downloader, and how exactly did that work? Krasimir Konov: Right, yeah. That was an interesting one, but not very unique or anything like that. We see that a lot with curl being used as a downloader. It's a very common malware. So rather than including the actual malware in the file, the attackers would use curl to download the malicious code. In this case, they'll download it from Pastebin, but it could be anything. It could be another website or anything like that, and curl would just make a call to the website, request the code. The website will respond with the code, and then later on, there is some code to either save the output somewhere on the website, or you'll just run it through eval and execute the actual code right away. Justin Channell: Right. And you said that it's commonly found in malware, but let's kind of maybe talk a bit broader about malware in general. What is everything that is classified as malware? Krasimir Konov: Well, in general it will be anything that the owner of the website didn't authorize, anything that was added by a third party. There is a lot of different malware. It could be even something like a defacement that will also be considered malware because it was something the user did not authorize. Even though it might not be doing anything malicious on the website, it's not infecting users, the visit is still something they did not authorize. So defacement would also be considered malware. And even something like ransomware where the website is technically not really damaged, it's all encrypted, but it's not infecting anybody. It's not doing anything malicious, but it's still encrypting the entire website and asking the user or the customer, the owner of the website for a ransom they need to pay in order to get the website back online. Justin Channell: Okay. Let's maybe break it down to each individual type of malware. For example, what would be a way that maybe I-frames could be maliciously used by a hacker? Krasimir Konov: Yeah. An I-frame can be used maliciously when it loads content from another location. You can look at the I-frame as a window that just opens another website. So anything that website has on it, you're pretty much loading it through the I-frame. So if that website is infected and it's serving some kind of malware, by opening an I-frame, you're loading all those elements, everything that was on this website. And sometimes the I-frame can be as small as pixel or something hidden somewhere off the screen, so you wouldn't even know that it was opening it. Justin Channell: And yeah, I feel like we've also seen a lot of them where they're used almost to mimic popups as well. Krasimir Konov: Yeah. I mean the I-frame, it could just load from another website and the other website could do anything. It could be serving just malware and it would try to infect the user that doesn't even know that they're being connected to the other website. It could just have some other JavaScript that's just trying to open up pop ups on the original website through the I-frame. Yeah, it could be a lot of things. Justin Channell: Okay. And also, let's talk a little bit about conditional redirects and how those work. What allows a script to detect which devices are coming in and where they're coming from? Krasimir Konov: Right. Yeah. That's a common one we see a lot. Basically, a conditional redirect would be something, it's a redirect on the website. It's obviously malicious, but there's certain conditions that need to be met before the redirect is actually executed or the redirect happens. For example, let's say if it's on a phishing website or a phishing page that is hidden somewhere on the website. For example, if Google visits it, obviously the attacker doesn't want Google to see the actual phishing page and record it as a phishing page. So they'll look for, for example, the IP address. They would look for the user agent. And a lot of times they can tell that it's a bot. So they'll just return a 404 response, for example, that will be like, "Oh, page not found." So Google would be like, "Oh, it looks like this page doesn't exist." But then if a regular user goes to the same page, then those conditions will be met. The actual website or the script behind the phishing will check and see, and be like, "Oh, this one is running Firefox or Chrome," and be like, okay. And then they'll look at the IP and be like, "Oh, he's in whatever, he's in United States somewhere." And he's like, "Oh, okay. That's good." And then once all of these conditions are met, then the actual script will serve them the actual phishing page. And it'll be like, "Oh, you need to fill out this to recover your account or whatever, or type in your credentials to log in here." Justin Channell: And so this is the type of thing we're really, a website owner is going to run into this more commonly when people are complaining about they're getting served bad content or whatever, and they can't seem to replicate it. It's likely probably these kind of redirects. Is that right? Krasimir Konov: Right, right. It could be something as specific as, for example, a range of IP addresses that correspond to an ISP or maybe let's say a country. It could be like, "Oh, were targeting only customers in the US," so if you're connecting from another country and you go to the same website or the same page, it would just say 404. It will give you a page not found. But then if you actually have an IP address from the United States, you're connecting from the United States, then it will actually show you the phishing page. Justin Channell: Now another type of malware I feel like we see a lot here is SEO spam. We hear people talking about that. What are some of the top SEO spam keywords that you see coming through? Krasimir Konov: Yeah. We get that a lot. We see a lot of spam on websites. A lot of times attackers will use SEO spam to gain ranking for their own website. Or they'll just try to include some kind of SEO spam in links to another website that they're currently running or something. I mean, these things change all the time. So a website might be up for a week and then it'll disappear, and then they'll start another campaign. But yeah, we see that a lot. We see all kinds of keywords they use. Most common ones will be something like Viagra. We'll have like jerseys for sale. A lot of times, they'll use name brands like Nike, Rolex, Prada. We've seen even some essay writing services for some reason. I'm not sure why, but that's common. We see, for example, pharmaceuticals a lot that will use specific medicine names. They'll use all kinds of replicas, like a replica bag of this, replica this, replica that. We'd see prescription, also payday loans. And obviously there's some adult related sites and things like that keywords. Justin Channell: So pretty much anything that people are going to be searching and clicking on are probably going to be targets for SEO spam? Krasimir Konov: Right. I think a lot of it commonly is pharma related because a lot of people are looking to buy medicine online, and a lot of times will require a prescription. So a lot of people are like, "Oh, let me see if I can find this medicine that I can buy it online somewhere." They don't need a prescription. They don't want to pay to visit a doctor and whatnot, and they'll look for it. And yeah. Justin Channell: Now, whenever somebody's website does get hacked with a SEO spam attack, what kind of effect can it have on the website beyond just being defaced? Krasimir Konov: Yeah. You can have a lot of things can happen, negative things. For example, the website can be blacklisted because of the keywords. And that usually represents a big red warning when you go on the website, depending on who blacklisted it. But if it's Google, for example, you'll see a big warning and it'll tell you this website contains malware or there's something wrong with this website. So, pretty much all the traffic on the website will be gone. And then you can also lose a lot of your reputation if there is a SEO spam on the website. For example, if you were ranked in say number five for certain keywords that represent your product on Google search engines, and then suddenly you get hit with SEO spam, then all these search engines then go and visit the website. And all of a sudden they're like, "Oh, there's all these weird key words on here, all this SEO spam that's causing a lot of mixed signals." And the search engines are like, "Oh, where do we rank this website now? Do we rank them with this product that's originally what the website is about? Or do we take into consideration all these other keywords that are mixed up that are SEO spam?" So, all of a sudden your website might go from being ranked number five on the first page to being on the 10th page. And then you rank for all these other keywords that you didn't intend to. And then people search for something completely different. They're searching for jerseys or something, or now they're searching for Prada products, and then suddenly your website pops up in there. So you're not really getting any good traffic, not targeted traffic. But, yeah. Justin Channell: Okay. So in a lot of ways, the effects of SEO spam would kind of be the same for defacements or any kind of malware with the blacklisting, but it does bring that kind of unique part to it where then it can also then bring traffic that you weren't expecting from somebody searching for jerseys, for example. I had not really ever thought about that. Krasimir Konov: Right, right. Yeah. It will definitely bring some traffic. I've seen a lot of times where websites will be connected. Let's say, there was 1,000 websites that were all infected with SEO spam, and it will kind of link each other to try to bring each other up into the rankings. And so you would see a lot of strange traffic from some random websites that were, for example, that were previously infected, even if they might not be anymore. But yeah, they'll be sending traffic to you or there'll be usually search engines sending you traffic, but for the wrong keywords. People are looking for something else, so obviously they're not going to be interested in your website. They're not going to buy anything because they're not looking for that. Justin Channell: And now, so thinking of the way websites get infected, a very common way it seems to be is through phishing campaigns. What are some recommendations you have for the best ways to avoid becoming a phishing victim? Krasimir Konov: Yeah. There is some ways. I mean, it depends really on the type of attack. Obviously, a lot of people, when they think of phishing, they think, "Oh, it's just like a PayPal phishing page and it just looks like the original," but it could be more subtle. If it's just a regular page where you're just going and you get redirected to another website, obviously the first thing to look is if you have the security padlocks, make sure that traffic is encrypted. A lot of these websites don't really have any encryption nowadays. More are starting to get that with pre SSLs being issued and whatnot. But that's the first thing to look and see, make sure. Anywhere you're typing your sensitive information, you want to make sure you have the padlock to make sure everything is encrypted. Krasimir Konov: But also you want to look at the URL of the actual website you're visiting. A lot of times they'll try to hide it. So you might have to be careful and look closely. Something that might be an I will be an L or something like that. And a capital I and L might look kind of similar into your IRL, so you might miss something like that. Say, if you're looking for PayPal and it might replace the L with an I, and if you don't look closely, it might look exactly the same. And you're like, "Oh, okay, it's paypal.com," but not really. So yeah. Just pay attention to the URL, make sure it is the actual website. There's no paypal.com dot something, dot something else, dot com. Yeah. You want it to just say paypal.com, and then it'll have forward slash and something else. But yeah, it gets more complicated when you have, for example, a phishing page that's injected into a regular page. For example, you have a checkout page on a website that you're buying things from and you go through the checkout page and you're looking at where you type in your credit card information and whatnot. And you might have a phishing page that actually looks exactly like a little box that gives you where you put in your credit card number, or your name, your address, and all that. So that will be more subtle. For example, that could be also an I-frame that's just coming from another page. And it will look exactly like it's part of the website. You're on the legitimate website, but only that portion of the website is actually the phishing page. And you look at it and you're like, "Oh, okay. It looks fine. I'm just putting my credentials." So that one could be a lot harder to figure it out. Usually, if it's something like that, I look for something that looks kind of out of place. Maybe they didn't get the right font. It might not be the same as the original website or there might be something out of place, some fields that are missing or some fields that are squished into the left or the right. It looks kind of awkward. It's like, why would this be like this? The whole website looks professional. There's a pink background or something, for example, and then suddenly there's this white box in the middle. It's like, ah, it looks kind of weird, out of place. Justin Channell: So pretty much if anything looks slightly out of place, you really should double check everything at that point. Krasimir Konov: Right. Right. Yeah. Obviously there's more ways that you can check, but I wouldn't get into more technical, like inspecting elements and looking at stuff, but yeah. Justin Channell: And now another type of malware that's kind of, and it kind of plays in with whatever the other infection is, is backdoors. Can you give us some examples of what backdoors can be? It's mainly just when a hacker can get back into the site to reinfect it, but I know there are a ton of different methods. And what are some of the more common ones and then maybe some that really interesting that you've seen? Krasimir Konov: Yeah, there is a lot. They'll probably be one of the first things the hacker would do is if they compromise a website, obviously they'll try to spread backdoors and just inject code everywhere so they can get back in, even if the owner of the website or webmaster cleans it. They want to try and hide some malicious code somewhere so they can always get back in. There's many variations. A backdoor could be something as simple as a single line of code to just [inaudible 00:20:19] argument, some kind of string or something via get or post. Krasimir Konov: And then it runs into an eval, so it evaluates the code and executes it. And some backdoors are very complex and they can be included in, let's say you have a WordPress site and you have a specific login page where all the login credentials are being processed and everything else. They could even inject code into that to basically bypass the whole login mechanism so that they can just bypass everything. They don't even have to know any user. They don't have to know the password, nothing. They'll just include some lines in there, and every time they'll be just able to log in. Yeah. It gets pretty crazy. Yeah. I mean, there's all kinds of malware. There is always a malware, for example, that just targets credit cards and will just target the eCommerce websites. And they'll just try to steal the login credentials, I mean, the credit cards. They'll try to get your address, your credit card information, any kind of CVV code or whatever you typed into the billing address, everything. And then there's also malware like the backdoors that are just trying to keep the attacker in control and trying to get them back into the website. There's just so many variations of what a malicious user might want to do on a website. Some can be something as simple as just reinfecting the website. They don't want to keep control. They just want to keep reinfecting it with some kind of malware. So even if you clean it, it would just get reinfected. Some of them in the database, otherwise might be in the files. We've seen some added into a [inaudible 00:22:14] job that just keeps running on the server. There could be malware that is just a giant to, for example, attack out of websites. Like for example, a distributed denial service where they put the same malware on thousands of websites. And then they try to send traffic to one website to try to bring it down. Yeah. People try to do all kinds of stuff with websites. We've seen even some cryptocurrency mining malware that you go onto a website and suddenly your PC starts running like crazy. And you're like, what the hell is going on? Your fans turn on and the PC is 100% CPU. And it turns out that the website has some malware that's just by mining Bitcoins with your CPU and it's using all of it. Justin Channell: Wow. Okay. So one question now, the last question I have is of all the malware that you've seen, what do you think is the coolest piece of malware that you've ever seen? Krasimir Konov: I think the coolest would be the ones that are so subtle that you don't even know that it's there. For example, we've seen some that were pretty innovative. It will be just a one liner code that's just one line. And for example, it will be let's say 40-50 characters, something like that. And that's all it is. And they'll hide it somewhere in between the legitimate code. And if you don't know what you're looking for, you would never see it. It doesn't look suspicious. There is no links to some other website. There's no some kind of encrypted code or anything like that. It's just a simple one line. And then if you're just scrolling through the file looking for something, you would never see it. It just looks like all the other code. And then if you look closely, you're like, "Oh, there's this..." Look closely, and you're like, "Oh wow, this is not supposed to be there." And then you keep looking at it and you're like, "This looks really weird." And then you see that it's actually doing some malicious things and trying to evaluate some code or taking output from the outside, I mean, some input from outside, you can call it and give it code to run. Justin Channell: Well, Krasimir, thanks for coming on and talking to us for today. Krasimir Konov: Yeah. Thank you. Thank you. I'm so happy. I'm glad I was able to do this podcast and I can't wait to do another one. Justin Channell: Yeah, we'll have you on again. Thanks. Krasimir Konov: Thank you. Justin Channell: Thanks again to Krasimir for joining us here on the Sit Down. We'll be back with another episode next month. So be sure to subscribe on Apple podcasts, Spotify, Stitcher, or any podcasting platform. Also, be sure to follow us on social media at Sucuri Security and check us out at sucuri.net. That's S-U-C-U-R-I.net. I'm Justin Channell, And this has been the Sucuri Sit Down. Stay safe out there.](https://blog.sucuri.net/wp-content/uploads/2020/05/20-sucuri-podcast-blog-post_blog_image-390x183.jpg)
Sucuri Malware Research Team
Fioravante Souza
Ben Martin
Luke Leal
Krasimir Konov