Urban Schrott, IT Security & Cybercrime Analyst at ESET Ireland, reports seeing more e-mail pretending to be from Microsoft is circulating, "warning" computer users that "Conflicker" is again spreading rapidly.
ESET's ThreatSense engine identifies the malware as Win32/Kryptik.CLU trojan, and running it would result in further malware infections.
Here's an example Urban quotes of one of the spoofed emails, though there are many more:
Subject: Conflicker.B Infection Alert
Date: Thu, 18 Feb 2010 20:15:30 +0900
Dear Microsoft Customer,
Starting 12/11/2009 the ?Conficker? worm began infecting Microsoft customers unusually rapidly. Microsoft has been advised by your Internet provider that your network is infected.
To counteract further spread we advise removing the infection using an antispyware program. We are supplying all effected Windows Users with a free system scan in order to clean any files infected by the virus.
Please install attached file to start the scan. The process takes under a minute and will prevent your files from being compromised. We appreciate your prompt cooperation.
Microsoft Windows Agent #2 (Hollis)
Microsoft Windows Computer Safety Division
Figures at Virus Radar, a resource we maintain to track threats circulating as email attachments, indicates an infection ratio of 0.036% today, putting it a close second to Win32/Zafi.B.
While these aren't the sort of volumes we regarded as high in the early noughties, that's a substantial ratio these days, when email attachments are not a particularly common vector.
In fact, we don't particularly publicise Virus Radar any more, as it comprises a very small proportion of the entire threat-range, and can easily be misinterpreted. However on this occasion, it does suggest a pretty determined spam run.