December 6, 2016
If you have visited any popular mainstream website over the past two months, your computer may have been infected — Thanks to a new exploit kit discovered by security researchers.
Researchers from antivirus provider ESET released a report on Tuesday stating that they have discovered an exploit kit, dubbed Stegano, hiding malicious code in the pixels of banner advertisements that are currently in rotation on several high profile news websites.
Stegano originally dates back to 2014, but since early October this year, cyber crooks had managed to get the malicious ads displayed on a variety of unnamed reputable news websites, each with Millions of daily visitors.
Stegano derived from the word Steganography, which is a technique of hiding messages and content inside a digital graphic image, making the content impossible to spot with the naked eye.
In this particular malvertising campaign, operators hide malicious code inside transparent PNG image’s Alpha Channel, which defines the transparency of each pixel, by altering the transparency value of several pixels.
The malvertising campaign operators then packed the altered image as an advertisement and managed to display those malicious ads on several high-profile websites.
According to the researchers, the malicious ads promote applications called “Browser Defense” and “Broxu,” and the methodology makes it tough for ad networks to detect.