The FBI has recently shut down a particularly nefarious ad server called the AdGholas group, which used a new and innovative method of infecting computers and managed to avoid detection for several months.
The hackers employed advanced steganography techniques via code embedded in graphics files, which marks the first time in history that malware has been served via steganography techniques.
That, however, proved to be just the tip of the proverbial iceberg. The company also employed a mind boggling series of checks to ensure that the machines redirected to servers that housed the exploit kits ultimately used to install the malware weren’t virtual machines used by security researchers, and met the various criteria that made them vulnerable to the attacks.
Between 10 and 20 percent of users who were served by AdGholas were redirected to servers armed with exploit kits. That doesn’t sound like a huge number, but given the fact that at its peak, AdGholas hit upwards of a million machines per day, the number ultimately impacted by malware is staggering.
Fortunately, thanks to decisive action by the FBI, the operation of the AdGholas network was suspended as of July 20. That’s undeniably good news, but now that the cat is out of the bag, you can bet we haven’t seen the last of this kind of attack.
Code delivered via steganography techniques is notoriously difficult to track, and virtually impossible to prevent. The reality is that none of the current antivirus and security software suites are equipped to detect or prevent this type of attack, and there’s no quick fix. There’s no patch or database update you can expect to see in coming months that will protect you from these kinds of attacks.
Hopefully, until that changes, the number of hackers who employ this method will be limited in number, but there’s just no way to be sure.