W32/Mytob.Y Worm

 Virus Information - W32/Mytob.Y Worm:

W32/Mytob.Y is a mass mailing worm. This worm is a variant of W32/Mytob.A. The worm will infect Windows systems and spreads through email.

The infected mail 'From' address prefix will be any one of the following;

adam, alex, alice, andrew, anna, bill, bob, brenda, brent, brian, claudia, dan, dave, david, debby, fred, george, helen, jack, james, jane, jerry, jim, jimmy, joe, john, jose, julie, kevin, leo, linda, maria, mary, matt, michael, mike, peter, ray, robert, sam, sandra, serg, smith, stan, steve, ted, tom

the suffix after '@' character will be any one of the following domains;

hotmail.com
cia.gov
fbi.gov
yahoo.com
juno.com
msn.com
aol.com

The subject of the infected mail will be any one of the following;

Good day
hello
status
test
Mail Transaction Failed
error
SERVER REPORT
read it immediately
thanks!
Mail Delivery System
(Variable String)

The infected attachment will be any one of the following;

message
document
readme
body
doc
file
test
text
data

The extension of the infected attachment will be any one of the following;

bat, cmd, doc, exe, htm, pif, scr, tmp, txt, zip

The body of the infected mail will be any one of the following;

The message cannot be represented in 7-bit ASCII encoding and has been sent as a binary attachment.

Mail transaction failed. Partial message is available.

The message contains Unicode characters and has been sent as a binary attachment.

The original message was included as an attachment.

I have received your document. The corrected document is attached.

(Variable string)

Upon execution of the infected attachment, the worm copies itself as msnmsgs.exe in the Windows System folder.

It also drops hellmsn.exe, funny pic.scr, photo album.scr and eminem vs 2pac.scr in the Windows installed folder.

The worm modifies registry at the following location to load itself during each startup.

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

To propagate itself, the worm scans the files having the following extensions and collects all the available email addresses from the infected system.

adb, asp, dbx, htm, php, pl, sht, tbb, wab.

It also collects email addresses from the Temporary Internet Files folder.