Researchers at Kaspersky Labs have detected an example of a breed of malware that uses a cross-browser plugin to create a worm that works across multiple browsers.
The LilyJade worm malware spoofs ad modules on Yahoo, YouTube, Bing, MSN, AOL, Google and Facebook. It spreads by publishing spam messages about teen popstar Justin Bieber from compromised Facebook accounts.
"This malicious program is a an excellent example of Malware 2.0-class programs based on modern web technologies, using social networks to propagate themselves and generating illegal incomes for their owners by spoofing various services," Sergey Golovanov, a Kaspersky Lab expert, wrote in a blog post on Monday.
The LilyJade worm used the 'Crossrider' cross-browser engine to make the virus work across version seven onwards of Internet Explorer, Google Chrome and Mozilla Firefox 3.5.
After analysing the virus, Kaspersky found it for sale for $1,000 (£790) online.
"There is NOTHING that can actively scan / detect this. No anti-virus is designed to look for this," ToXiiC wrote on a virus forum. "All your victims will be high quality, up to date machines."
The virus highlights the risks companies open themselves to when letting employees access social media at work.