Last week Trend has reported about a new variant of Cryptolocker worm. In Trend Micro terminology -> WORM_CRILOCK.A (http://about-threats.trendmicro.com/us/malware/worm_crilock.a) - this is being detected by Symantec as Trojan.Cryptolocker.B (http://www.symantec.com/security_response/writeup.jsp?docid=2013-122312-5826-99). In a difference to previous variants of Cryptolocker this particular variant spreads over removable devices. Another significant difference is that it does not rely on a malware downloader routine any more to infect the systems but instead works as activator for software like Office or Adobe Photoshop in P2P sites.
New CryptoLocker Spreads via Removable Drives
On how to defend against the Cryptolocker threats please check following Symantec publications:
Cryptolocker: A Thriving Menace
Cryptolocker Alert: Millions in the UK Targeted in Mass Spam Campaign
Cryptolocker Q&A: Menace of the Year