Although the malware, labelled a worm by Microsoft and tagged as “Win32/VB.CB” by the company, is ineffective against Apple’s iOS and OS X operating systems, it may pose a threat to iTunes customers who download iPhone and iPad apps to their Windows PCs before syncing to their mobile devices.
The worm was reported to Apple‘s support forum by a user on Tuesday, who said that his or her OS X antivirus warned that “Instaquotes-Quotes Cards for Instagram” was infected.
“I just downloaded two apps from iTunes and one of them has been flagged by ClamXav as being a virus,” wrote deesto.
While others commenting on the same support thread initially suspected the warning may have been a false positive by the antivirus software, CNET confirmed that the app was, in fact, harbouring the worm.
Tech website Computerworld extracted the app’s .ipa archive — the packaging format Apple uses to deliver its apps — on a Windows 7 PC, then scanned the system using Microsoft’s free Security Essentials antivirus program.
Security Essentials flagged the file and warned that it contained Win32/VB.CB.
According to Microsoft’s website, the worm harks back to 2008 and is known by several other names, including W32.Imaut.AS (Symantec), W32/Autorun.worm.h (McAfee) and W32/VB-DGA (Sophos).
Microsoft said that the worm “attempts to spread via Yahoo! Messenger … [and] may also connect to a remote server to download arbitrary files.”
Another commenter on the support thread downplayed the threat, even to Windows users and posed a possible explanation for the infected app.
“It is nothing to worry about,” said the commenter, tagged as “etresoft,” several hours after deesto opened the discussion. “Considering where this virus is located, it wouldn’t even hurt a Windows machine. It looks like an accident from the developer’s infected Windows machine.”
Instaquotes-Quotes Cards for Instagram, launched July 19, is no longer on the App Store.