Menu
Long-running malvertising campaign infected thousands of computers per day

Long-running malvertising campaign infected thousands of computers per day

The AdGholas malvertising operation tricked ad networks and malware scanners using steganography

Security researchers have shut down a large-scale malvertising operation that used sophisticated techniques to remain undetected for months and served exploits to millions of computers.

The operation, dubbed AdGholas, has been running since at least October 2015. According to security vendor Proofpoint, the gang behind it managed to distribute malicious advertisements through more than 100 ad exchanges, attracting between 1 million and 5 million page hits per day.

The Proofpoint researchers estimate that 10 to 20 percent of computers that loaded the rogue ads were redirected to servers hosting exploit kits -- web-based attack tools that attempt to silently exploit vulnerabilities in popular applications in order to install malware.

The malvertising code used a series of complex checks to ensure that the visiting computers are not virtual machines used by security researchers or by ad networks themselves to discover malware.

Other checks were used to filter victims based on their geolocation and to serve certain malware programs, typically online banking Trojans, only to users in specific regions. This was likely done on request by the cybercriminal gangs behind those Trojans that paid the AdGholas group to distribute their malware.

In order to make it even harder for ad networks and security scanners to discover the attacks, the AdGholas group used steganography -- the technique of hiding code inside images. The rogue ads contained images with encrypted JavaScript code inside that was only extracted and executed for selected computers passing the required checks.

This is the first time when the use of steganography has been observed in a malvertising attack, according to Proofpoint. The company's researchers worked with researchers from Trend Micro to deconstruct the attackers' technique and analyze it.

Proofpoint estimates that the AdGholas malvertising campaigns hit up to 1 million computers every day and infected thousands of them with malware. The operation was suspended on July 20 following action from members of the advertising industry.

Subscribe here for up-to-date channel news

Follow Us

Join the New Zealand Reseller News newsletter!

Error: Please check your email address.

Featured

Slideshows

StorageCraft celebrates high achievers at its inaugural A/NZ Partner Awards

StorageCraft celebrates high achievers at its inaugural A/NZ Partner Awards

Revealed at a glitzy bash in Sydney at the Ivy Penthouse, the first StorageCraft Partner Awards locally saw the vendor honour its top-performing partners with ASI Solutions, SMBiT Pro, Webroot, ACA Pacific and Soft Solutions New Zealand taking home the top awards. Photos by Maria Stefina.

StorageCraft celebrates high achievers at its inaugural A/NZ Partner Awards
Kiwi resellers make a splash on Synnex and Lenovo RotoVegas road trip

Kiwi resellers make a splash on Synnex and Lenovo RotoVegas road trip

​Synnex and Lenovo hosted 18 resellers for an action-packed weekend adventure in RotoVegas, taking in white water rafting on the Kaituna River, as well as quad biking and dinner at Stratosfare​, overlooking Lake Rotorua at the top of Mount Ngongotaha​. Photos by Synnex.

Kiwi resellers make a splash on Synnex and Lenovo RotoVegas road trip
Show Comments