Online Scanner Top Twenty for November 2006

Position	Change in position	Name	Percentage
1.	+2	Trojan-Downloader.Win32.Delf.awg	2.77
2.	New	Trojan.Win32.Dialer.hc	2.61
3.	New	Trojan.Win32.Dialer.hh	2.23
4.	New	Email-Worm.Win32.Warezov.gj	2.17
5.	New	Email-Worm.Win32.Warezov.ev	1.56
6.	New	Trojan-Clicker.Win32.Small.kj	1.46
7.	+1	Email-Worm.Win32.Brontok.q	1.26
8.	+8	not-a-virus:AdWare.Win32.Softomate.u	1.23
9.	New	Trojan.Win32.Dialer.hz	1.16
10.	+4	Email-Worm.Win32.Rays	1.07
11.	New	Email-Worm.Win32.Warezov.gc	0.99
12.	-5	Backdoor.IRC.Zapchast	0.95
13.	New	Email-Worm.Win32.Warezov.gl	0.90
14.	New	Email-Worm.Win32.Warezov.fh	0.73
15.	New	Trojan-Spy.Win32.Bancos.zm	0.60
16.	New	Trojan-Dropper.Win32.Small.asx	0.58
17.	+2	not-a-virus:PSWTool.Win32.RAS.a	0.53
18.	Return	Trojan-Downloader.Win32.INService.gen	0.52
19.	New	Email-Worm.Win32.Warezov.gk	0.51
20.	New	Trojan.Win32.Dialer.cj	0.49
Other malicious programs			75.68

In October, Warezov.cc took first place in our online statistics, with an unprecedented 13.33%. In November, not a trace remains of this worm. On one hand, this is good news because it shows that this particular worm has completely stopped spreading. On the other hand, there are six new representatives of the Warezov family in the online Top Twenty, proving that Warezov remains the most dangerous malicious program on the modern Internet. Furthermore, fourth and fifth place are occupied by Warezov.gj and Warezov.ev, the leaders of our email Top Twenty. Such a clear correlation between our two different reports on virus activity is a rare event. Usually, the leaders of email rankings don’t figure in the online Top Twenty at all.

Curiously, none of the seven new Warezov variants that came up in our October statistics are left in November. Overall, the family as a whole is keeping a much lower profile in terms of percentage points compared to a month ago.
In contrast, September’s leader, Trojan Delf.awg, is back in first place. This simple program which is designed to install other Trojans on infected computers remains a “phantom menace”. Quite conceivably, it may be one of the sources of the Warezov epidemic. At any rate, there’s some connection between these very different malicious programs.

We wouldn’t have expected to see so many dialer Trojans in our statistics, especially as high as the second and third positions. Four in one month is strange; such Trojans were widespread between 2002-2004, but since then they’ve decreased in number. Their mechanism is quite simple. After making their way onto a computer they call premium rate numbers. As a result, the owner of the infected computer is charged a hefty sum by the phone company. One would think that with broadband Internet access becoming more accessible this type of cybercrime would become less common, but… December’s statistics will show whether this is a one-off surge or whether dialers are staging a full scale comeback.

Among the other malicious programs which make up this month’s Online Scanner Top Twenty, Rays and Brontok (both worms) deserve a mention for their sheer tenacity. They’re not very good at spreading via email, but on an infected computer they show what they are capable of: they not only flood the computer with their copies but try to spread on other machines on the network as well.

Softomate.u, an advertising program (AdWare), is continuing to spread. There are several IM worms which send links to this program to those on the contact list of the victim machine, and these worms are the main driving force of the epidemic.

Summary