What is Malvertising & How Do You Avoid It?

One day, while surfing the web, you click on an ad for a Black Friday Sale. The moment you do, a security alert pops up with a warning that Your Computer may be Compromised. To fix the issue, it asks that you download an application. You would click on the link, thinking this could be a potential solution. The download page claims to have a solution to your problem, but in reality, it infects your computer with malware, which slows it down and compromises your data.

You were not aware that this was not an advertisement; rather, it was a kind of malvertising, in which dangerous code is hidden under ads to corrupt your device.

In this blog, we’ll examine how malvertising operates, how it impacts users, and how you can avoid falling for these harmful advertisements.

How Malvertising Operates

Malvertisements are spread all over the Internet and can be found on both fake and real websites.

Usually, the advertiser runs the malvertising regardless, as most of the time, they are unable to detect if it is damaging. When a business decides to run an ad, it is sent to websites that aren’t harmful through a server. When someone hits on the malicious ad, code begins to run in the background, which could lead to the downloading of malware onto the user’s computer. This is referred to as a drive-by download.

Sometimes, the user doesn’t even have to click on the malicious ad for the drive-by download to work. They can get the malware as long as they load an infected site or landing page. But if someone clicks on malware, they might be taken to a different page that is meant to take advantage of flaws in their browser when it shows ads.

Malvertising attacks sometimes also use an exploit kit, a kind of malware that explores a system and exploits security weaknesses.

Before you can understand how complicated malvertising is, you need to know how it’s different from other types of online threats. Now, let’s take a closer look at how it compares to another common online security risk.

Malvertising vs. Adware: The Key Differences

People often get confused between advertising Malware and Adware. Adware is a software that is installed without our knowledge or comes with genuine software. Adware displays unwanted advertisements in your web browser, transmits your search queries to advertising websites, and collects information about you to make advertisements relevant to you.

To keep in mind, ad spyware and malvertising differ clearly:

Malvertising is the act of injecting malicious code onto a publisher’s website to target specific users. Adware, on the other hand, is made to target people without being placed on a publisher’s website first.

Also, malvertising only affects those who visit an infected website; adware stays on a user’s machine upon activation and runs continuously.

All things considered, malvertising and adware differ in their operations and purposes. While adware sits on a user’s machine and serves advertising continuously, malvertising depends on compromised websites.

After identifying the main distinctions, let’s examine how these damaging advertisements may affect the people who see them.

How These Ads Harm Users

Malvertising can affect people who see harmful ads, even if they don’t click on them. Some of these are:

• Drive-by download attacks: This happens when adware or malware is placed on a computer without user knowledge. This could happen if their browser is compromised.
• Forced browser redirects: People may be sent to harmful websites against their will, putting them at risk of harm.
• Without permission, annoying ads, malicious content, or pop-ups: Malvertisements may use JavaScript to show more ads or content than what the ad network is allowed to show.

When users click on a malicious ad, malvertising can compromise their security:

• Installation of malware or adware: If a person clicks on a malicious ad, code can run on their computer and install harmful software.
• Redirect to a malicious website: Users may not reach the place the ad suggested but instead, be taken to a site that puts their online safety at risk.
• Phishing attacks: Malicious advertising may trick users into disclosing private information by directing them to websites that look real.

It is important to be aware of these risks and take necessary precautions to protect oneself while browsing the internet.

We can see that malvertising puts people at great risk. What about companies that depend on online ads, though? Let’s look at The Impact of Malvertisements on Publishers to see how these threats also affect them.

The Impact of Malvertisements on Publishers

Attackers can cause companies a great deal of damage when they acquire an ad network. Their reputations suffer, site traffic and sales decrease, and they might even be sued for the harm they caused users.

Publishing companies are aware of this problem, but it’s still hard to find and block rogue ads. Thanks to real-time bidding, ad networks show ads from a huge number of marketers and change them constantly, making it very hard to fully test every ad that users see.

Publishers face serious consequences when malvertising infiltrates their ads. Now that we’ve seen the problem, let’s explore how these malicious ads get inserted in the first place.

Methods of Malware Insertion into Ads

• Malware in ad calls: When a website shows an ad, the ad exchange sends the ad through a third party. Bad people can get into one of these third-party sites and add harmful code to the ad payload.
• Malware-injected post-click: When someone clicks on an ad, they are taken to several different URLs before they reach the ad landing page. If an attacker gets into any of these URLs, they can run harmful code.
• Harmful code in ads: Harmful code can be included in text or banner ads. For example, HTML5 lets ads use both pictures and JavaScript, which could contain harmful code. This is especially dangerous for ad networks that use the Flash (.swf) file.
• Malware in a pixel: Pixels are pieces of code that are put into ads or landing pages to track information. Real pixels only send data, but if an attacker blocks the pixel’s delivery, they can respond to the user’s browser with malicious code.
• Malware within video: Video players do not protect against malware. As an example, common video formats (VAST) can have pixels from outside sources that may contain harmful code. Users can get infected by videos that end with a harmful URL.
• Malware in Flash videos: Flash videos can add an inner frame (iframe) to the page, which lets malware download without the user having to click on the video. Pre-roll images that load while the video file loads can also have malicious code added to them.
• Malware on a landing page: Even on legitimate landing pages hosted by trustworthy websites, parts that can be clicked on may run harmful code. This kind of malware is especially dangerous because when people click on an ad, they go to a real landing page but are affected by something on the page.

There are various methods of inserting malware into ads. Knowing this helps us understand how to defend against these attacks. So, how can we prevent malvertising?

Strategies to Prevent Malvertising

Malvertising is a difficult attack to spot and stop, and both end users and producers need to take action.

How Users Can Avoid Malvertising

To protect yourself from malvertising, you should practice good online hygiene, keep your software up to date, and use a variety of protection tools:

• Keep your software up to date: Regularly updating your browser, operating system, and plugins will help you have the latest security modifications. Old software often contains security vulnerabilities that hackers can target.
• Use an Ad-blocker: An ad-blocker is useful because it prevents many forms of advertising from running on web pages.
• Disable JavaScript and Flash: Malicious code is often sent through JavaScript and Flash. Turning these off can stop many types of malware attacks, but it may also make some services less useful.
• Watch Out for Pop-ups: Avoid clicking ads, or windows opening in pop-up windows. Rather, close them using task manager or the “x” button.
• Use Antivirus Software: Good antivirus means the chance of malware for you is minimum, as it detects it before it impacts. Ensure you update your antivirus program regularly.
• Turn on “Click-to-play”: With “Click-to-play,” the user must click to play multimedia content. This could prevent harmful code from running by default.

To mitigate the risks of malvertising, publishers can take several steps:

• Check out ad networks carefully to make sure they have a good image and strong security measures in place. It’s important to find out how ads are delivered and what steps are taken to stop harmful ads.
• Ad content should undergo a strict scanning process before it is shown. This will help find malware or other annoying software that could harm users’ devices or compromise their security.
• You could decide to make a rule that limits the types of files that can be used in ad frames. Malicious content is much less likely to occur if you only use safe forms like JPG or PNG and avoid JavaScript and Flash.

By following these practices, publishers can minimize the impact of malvertising and maintain a safer environment for their users.

Conclusion

Malvertising poses a danger to both users and publishers, but you can guard against its negative impacts by taking the appropriate steps. You can lessen your vulnerability to these assaults by using ad blockers, upgrading your software frequently, and remaining aware.

FAQs

1. How do I get rid of malvertising?

To eliminate malvertisements, keep your software up-to-date, disable JavaScript and Flash, use an ad blocker, and routinely check your device with antivirus software.

2. What is an example of malvertising in real life?

Malvertising happens when an ad on a safe website has malicious code that infects a user’s computer with malware when they visit the site, even if they don’t click on the ad.

3. What is malvertising, and how do you protect against it?

Malvertising is the practice of inserting malicious code into online advertisements, frequently leading to virus downloads or user redirects to dangerous websites. To defend yourself from malware, use antivirus software, avoid clicking on dubious advertisements, use ad-blockers, and keep your software updated.

If you’re interested in learning more about the Cybersecurity landscape and taking your skills to the next level, the CEH Course is a great place to start. This course will provide you with a thorough understanding of ethical hacking techniques and equip you with the tools needed to safeguard networks and systems. It’s an excellent opportunity to build a career in one of the most in-demand fields in cybersecurity.