On 21 August 2003 Symantec Security Response upgraded the W32.SOBIG.F threat to a category 4.
It is the sixth version of this worm.
SOBIG.F follows a computer worm known as "Blaster," or "MSBlaster," which infected at least 500,000 computers all over the world only a week ago. The “Nachi” worm which is designed to protect pcs from “Blaster” caused its own havoc including infiltrating unclassified computers on the Navy-Marine intranet and the collapse of the check-in system of Air Canada.
Associated Press has stated that 1 in 17 emails sent around the world has been infected.
According to Paul Wood of MessageLabs it took anti-virus companies at least 12 hours to release updated software to combat the worm.
W32.Sobig.F@mm is, in fact, a worm, not a virus. This worm sends itself to every email address it finds in files with the following extensions:
- .TXT
- .WAB
- .MHT
- .HTML
- .HTM
- .HLP
- .EML
- .DBX
The “SOBIG” worm is found in emails in your inbox with the following subject headings:
- RE: DETAILS
- RE: THANK YOU!
- RE: YOUR APPLICATION
- RE: YOUR DETAILS
- RE: DETAILS
- RE: APPROVED
- RE: THAT MOVIE
- RE: WICKED SCREENSAVER
I have personally received emails with all of these subject headings on a daily basis. The body of the email simply refers you to an attached file. It is absolutely critical that you DO NOT open this attachment. It is this attachment that contains the “SOBIG” worm.
The “SOBIG” worm is attached to files with the following names:
- Movie0045.pif
- Your_document.pif
- Thank_you.pif
- Document_all.pif
- Details.pif
- Document_9446.pif
- Wicked_scr.scr
- Application.pif
The last day on which the “SOBIG” worm will spread is 9 September, 2003. Although this means email address collection and mass-mailing will stop at that date a computer infected with the worm will still try to download updates from master servers even after this date.
The worm affects Windows 95, 98, Me, Nt, 2000 and XP but leaves Unix, OS/2, Windows 3.x, Macintosh and Linux unaffected.
Thankfully Symantec Security Response has created a removal - continued below ...