Ars Technica used in malware campaign with never-before-seen obfuscation

Ars Technica was recently used to serve second-stage malware in a campaign that used a never-before-seen attack chain to cleverly cover its tracks, researchers from security firm Mandiant reported Tuesday.

A benign image of a pizza was uploaded to a third-party website and was then linked with a URL pasted into the “about” page of a registered Ars user. Buried in that URL was a string of characters that appeared to be random—but were actually a payload. The campaign also targeted the video-sharing site Vimeo, where a benign video was uploaded and a malicious string was included in the video description. The string was generated using a technique known as Base 64 encoding. Base 64 converts text into a printable ASCII string format to represent binary data. Devices already infected with the first-stage malware used in the campaign automatically retrieved these strings and installed the second stage.

Mandiant researchers said there were no consequences for people who may have viewed the image, either as displayed on the Ars page or on the website that hosted it.