Malware analysis

Malware Spotlight: What is adware?

August 27, 2019 by Greg Belding


Face it — we’ve all been there. You’re blissfully surfing away on the internet and then suddenly your web browser starts popping up windows for advertisements out of seemingly nowhere. Your PC suddenly starts performing much more slowly and whenever you’re online, you keep seeing those same advertisements. 

Welcome to the world of adware. It’s annoying at first, but it can also be what ultimately allows attackers to run your once-trusty system into the proverbial ground. 

This article will detail what adware is, a little about how it works and some common types of adware. We’ll also provide some tips for how to protect against and remove adware from your system.

What is adware?

Adware refers to advertising-supported malware. This is malware that displays advertisements on computers and can change browser search results in order to generate money for the adware creators with user clicks. It can also collect marketing data about the user that it victimizes. 

These software applications can be automatically downloaded from just clicking around an infected website. Adware can even piggyback onto other applications and software you install. 

While not quite is dangerous and destructive as worms, Trojans, ransomware and other viruses, adware is a serious concern that all computer users need to address at some point. Otherwise, their system will soon be a money-generating slave system for the adware creators.

Adware detections have been decreasing in recent years, according to a recent report from Malwarebytes, but this does not lessen the threat. This is based on the very driving force of the internet — the financial forces of advertising. Attackers know this value well and are still ready, willing and able to dedicate a substantial amount of their cybercrimes to distributing adware.

What’s so scary about this big bad wolf?

Yes, adware is not the end of the world in terms of attacks, but it can be the starting point of some pretty awful things that can happen to your system. 

First, they can drastically slow down computer systems and make web browsers run as slow as molasses. Second, and worst of all, they can provide a backdoor into computers for cybercriminals to implement other treats, steal other data and potentially gain access to every device in your network. Looks like those shopping-focused internet browsing sessions can cost you more than the sale price you got that shirt for. 

How exactly do you become infected?

Adware has two main methods of initially infecting systems. The first is by downloading shareware or freeware that installs adware onto your system without your permission or knowledge. 

The second, considered to be the “dirtier” method, is by infecting a system that visits an infected site. A typical example is when a user visits an infected site and the adware exploits a security vulnerability in the web browser. The adware delivers a drive-by download which causes more advertisements to pop up on your system, collects more information about you and can redirect you to malicious sites.

How does adware spread?

There are four main ways of spreading adware:

  • Botnets: Botnets are used as malicious program distribution platforms that offer cybercriminals pay-per-install fundraising. Due to the ability of botnets to distribute all kinds of malicious programs, adware can be a sign of worse things to come
  • File sharing sites and torrents
  • Browser extensions: Internet Explorer is the most infamous infection vector of these
  • Legitimate programs that contain adware and adware-like components, including browser extensions

Types of adware

There are many different types of adware that have slightly different ways of infecting systems and delivering load after load of adware pain to users. 

  • Gator
  • Fireball
  • DeskAd
  • BioNet
  • WeatherBug
  • DollarRevenue
  • ClickSpring
  • Bonzi Buddy
  • PuzzleDesktop

How to detect adware

Unlike practically every other malicious action performed on a system with the exception of ransomware, adware is the easiest to detect. 

The first sign most users notice is a slower computer and web browser with advertisements that pop up out of nowhere. This should be the point at which you run an antivirus scan on your computer. Despite it being too late to stop the infection, at least you’ll know what is causing the decline in performance. 

If you have ignored the obvious signs, you’ll soon have a system that approaches a point of the system being too slow to use at all. Before I became security-minded, my first PC became so infected that it approached a point of hijacking that was almost like ransomware. (This was in the pre-ransomware era, too.)

How to remove adware

The first step to removing adware is to make sure your security patches are all updated. Once you have up-to-date security patching, you can mount your attack. 

Most antivirus solutions have the ability to remove adware from systems. Schedule a system scan with your antivirus solution and take the appropriate steps to delete the adware, as prompted by your antivirus. 

It should be noted that some adware has the ability to hijack your system to a point where your antivirus is prevented from running a scan and your system can no longer update. When this happens, it may be too late, and a system reset or reimaging may be required to bring your system back to its former performance level. 

You know what they say — an ounce of prevention is worth a pound of cure. Knowing this information, only the most negligent system administrator or owner would not respond to the obvious signs of an adware infection.


Adware is, unfortunately, still a common part of the web browsing experience for many. Despite a seeming reduction in adware infections in recent years, the threat persists, as your information is still valuable to both cybercriminals for marketing purposes and adware can be the backdoor for other malicious activity on your system. 

Keep in mind that adware is easy to detect, so stay vigilant, and any adware infections you get shouldn’t spread very far.



  1. Types of Adware: AdDestroyer, Spam Laws
  2. All about adware, Malwarebytes
  3. What is Adware? Tips for Preventing and Removing, Panda Security
  4. What is adware? How it works and how to protect against it, CSO
Posted: August 27, 2019
Greg Belding
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Greg is a Veteran IT Professional working in the Healthcare field. He enjoys Information Security, creating Information Defensive Strategy, and writing – both as a Cybersecurity Blogger as well as for fun.