Apple updates anti-malware software against Reddit-managed botnet

Apple has updated its anti-malware software Xprotect to protect against Mac.BackDoor.iWorm; malware that makes a Mac part of a botnet that is managed via Reddit, among other things. There are said to be more than 17,000 infections.

A new version of Xprotect contains references to iWorm.A and iWorm.B, Macrumors discovered. Apple seems to have quietly implemented the new malware definitions. With the new version of Xprotect, Mac users should be protected from Mac.BackDoor.iWorm, which includes infected Macs in a botnet.

A Russian antivirus company discovered Mac.BackDoor.iWorm and found that more than 17,000 Macs have already been infected with the malware. Notably, compromised systems use Reddit to connect to the botnet. The administrators distribute a list of botnet servers via Reddit, which can only be found with a certain search term. The search term is based on the md5 hash of the current date.

Xprotect was introduced by Apple with OS X Snow Leopard and warns of the presence of malware on the Mac. Updates are downloaded automatically.