Microsoft Lists Top 10 Windows Malware

It's been a while since we've done a good top malware threats list here, but a new list just came out from Microsoft based on their MSRT, or Malicious Software Removal Tool. This is a tool that runs every month at Patch Tuesday time, so it has very broad, worldwide reach. The downside to it is that it searches for and removes a list of malware that is small compared to that of a real anti-malware product (well, it's a lot bigger than Apple's list, but Microsoft has a bigger problem and perhaps we should give Apple some time).

The top 10 threats removed by the tool:

Family	Threat Count	Machine Count
Taterf	544,662	463,000
Renos	308,789	228,973
Alureon	249,101	211,441
FakeRean	219,359	162,328
Bancos	173,134	158,152
Koobface	274,769	134,139
Frethog	140,218	132,827
Cutwail	166,284	110,840
Rustock	98,673	90,788
Tibs	93,175	84,081

Off the top of my head I only recognize the names Koobface, Bancos and Renos. Koobface is clearly a major threat, but it gets a lot of attention because its Facebook association makes it a sexy story. How many of you have heard of Taterf? Microsoft's definition of it describes it as "...a family of worms that spread via mapped drives in order to steal login and account details for popular online games." CA's description indicates that other vendors, including Symantec and McAfee, use a generic "Trojan" moniker, which perhaps explains the Taterf name's anonymity.

The top 10 threats were cleaned from a total of 1,776,569 machines. The country data below makes clear that there are a lot of machines not in the top 10 list.

Country/Region	Threat Count	Machine Count
US	8,750,628	2,183,166
China	1,085,140	383,378
Brazil	737,322	282,152
UK	1,078,540	278,207
Korea	601,646	262,539
France	412,115	156,566
Taiwan	236,047	140,283
Spain	328,829	133,264
Canada	433,770	119,885
Mexico	447,841	117,845