Original URL: http://www.theregister.co.uk/2004/10/27/myflip_virus/
Virus experts fret over Myfip
Previously-unknown packing utility
The Myfip worm which was discovered in the wild a month ago is starting to spread, according to email security firm MessageLabs.
The worm assumes the guise of an email from a webmaster at eBay. The email asks the recipient to take part in a 'Multiple Item Auction' with the chance of winning a prize. But the worm's most worrying characteristic is its use of a previously unknown packing utility.
There are a number of different utilities available to virus authors that allow them to compress and encrypt their viruses. Inexperienced authors often use common packing programs that are readily available on the internet. With the Myfip worm, the virus writer is using what is termed a nested compression technique - meaning that the file is compressed numerous times - which serves to confuse mail scanners according to Conor Flynn, technical director at Irish security firm RITS.
"Myfip uses a packer previously unseen in email virus distribution. The use of an uncommon packer could make it more difficult for antivirus software vendors to identify and protect against the malicious code within," according to MessageLabs.
The worm, once initiated, searches an infected computer for poorly protected network drives. It then copies itself to those drives using a file tagged "Iloveyou.txt.exe". Security firm, Symantec has said that if the worm encounters password-protected drives it will attempt to log on as an administrator by using a list of common passwords.
"Antivirus vendors have issued updates to deal with this threat but it is up to individuals to download these patches independently," said Flynn, speaking with ElectricNews.Net. "Vendors have said that they will be including a code change to handle this threat in their next releases," Flynn added.
The worm, though spreading, is not exceptionally virulent at the moment. Whilst security experts have not rated Myfip as a high-level threat the way in which is it travelling - through the uncommon packer - is worrying and could be indicative of a new trend in virus writing, experts have said.
Due to the increasing number of viruses in recent times people have become more wary of opening attachments, explained Flynn. MessageLabs also cited the poorly written text in the Myfip email is using as something which should arouse suspicion in PC users.
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