Top Tracked Viruses
Thursday, July 8th, 2010McAfee maintain a list of the current top tracked viruses and their characteristics.
The current list of prime suspects is most illuminating. Most are trojans, but two are worms:
- Exploit-ObscuredHtml
- Exploit-MS06-006
- Generic!atr
- HTML/FakeAV
- Exploit-PDF.b.gen
- Generic PWS.ak
- W32/Conficker.worm!inf
- W32/Rimecud
- Generic FakeAlert!cr
- Bredolab.gen.d.
As to which are trojans and which are viruses, the clue is in the title of one, but it’s not so easy in the other. The infamous W32/Conficker.worm!inf is one and the other is W32/Rimecud.
But lets have a look at one of the trojans first. Exploit-ObscuredHtml. To remind ourselves, this is a trojan and it’s so-called because its takes it lesson from ancient Greece mythology. They are spread inadvertently by people who think that they are downloading, or swapping to someone else, a file which is of some use. In reality, it’s an illegal gateway to someone’s computer. And because unlike viruses they don’t replicate, they rely on manual distribution methods such as email, malicious, or hacked web pages, Internet Relay Chat (IRC), or peer-to-peer networks.
Now Exploit-ObscuredHtml is an exploit by sub-type and it exists as code in an email message, web page, or HTML document.
Interestingly, certain non-ascii characters are ignored by Microsoft Internet Explorer, allowing an attacker to obfuscate malicious code. And still have it rendered by Internet Explorer. But the detection of this particular trojan covers HTML documents that have been crafted with the intention of evading antivirus detection. And there are other documents that mix HTML with non-ascii characters which could also trigger this detection.
Now lets take a brief look at the W32/Conficker.worm!inf. The Conficker caused virtual panic in the media earlier in 2009 and its was dubbed the mother of all viruses. Actually it has been around for some years, although this version was particular virulent.
The sub-type is a worm and it is a file which is usually dropped onto the root of all removable drivers and mapped drives in an attempt to autorun an executable when the drive is accessed.
IT people can spot infection when they see the prescence of autorun.inf files on the root of all removable drives or mapped network drives containing specific information.
Guest Article by Neil Camp


My name is Alan Potts and I'm the Editor of the Antivirus-BUYability web site and Managing Director of BUYability Limited. You can connect with me or keep up to date with new posts on this blog via the following social media sites: 








