Oh this is a throw back to the 90s, a self-replicating e-mail worm based around a malicious screensaver (.scr) that sends itself to everyone in your address book. It seems this one is spreading fast though with hundreds of thousands of infections.
Reminds of the heydays of ILOVEYOU and Anna Kournikova.
A fast-moving email worm that began spreading on Thursday has been able to affect hundreds of thousands of computers worldwide, anti-virus provider Symantec warned.
The email arrives with the subject “Here you have.” An executable screensaver that’s disguised as a PDF document then tries to send the same message to everyone listed in the recipient’s address book. The .scr file is a variation of the W32.Imsolk.A@mm worm Symantec discovered last month.
In addition to spreading through email, it can propagate through mapped drives, autorun and instant messenger. It also has the ability to disable various security programs.
It’s slightly more advanced than the old versions though with the ability to spread through instant messaging (probably MSN Live Messenger) and also disable security programs.
Plus it’s harder to scan for as the malicious screensaver isn’t actually attached to the email but downloaded from a remote source, and from early reports – multiple remote sources.
The worm is a throwback to attacks not seen in almost a decade, when the Anna Kournikova and I Love You attacks wreaked havoc on email systems worldwide. The Here You Go worm appears to different in that the malicious payload is downloaded from a page on members.multimania.com, rather than being attached to the email. That could make efforts to eradicate the worm easier.
Then again, McAfee said multiple variants of the worm appear to be spreading, so it’s not yet clear that the malicious screensaver is hosted by a single source.
There’s more info available here:
Source: The Register