W32/Mytob.V Worm

 Virus Information - W32/Mytob.V Worm:

W32/Mytob.V 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;

(Variable String)
Error
HELLO
Hello
Hi
Mail Delivery System
Mail Transaction Failed
Server Report
Status
hello
hi

The infected attachment will be any one of the following;

(random characters)
body
data
doc
document
file
message
readme
test
text

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

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

The worms inserts the following extension to the infected file if the extension of the file is zip:

.doc, .htm, .html, .txt.

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.

test

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

(Variable String)

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

The worm attempts to locate SMTP server by appending the following prefixes to the domain names collected from the infected system. On successful SMTP server access it mails itself to the collected email addresses.

mx.
ns.
relay.
mail1.
mxs.
mx1.
smtp.
mail.
gate.