The risk of new worm named Bagle.B is being upgraded by internet security companies because of its quick spreading.
The malware contains its own SMTP engine to construct outgoing messages, collecting email addresses from the victim machine. As usual in the current wave of mass e-mailers, the From: address of messages is spoofed. It's interesting to note that this program contains a remote access component that notifies the hacker when a machine is infected.
The worm wil stop replicating from 25th February 2004.
According to McAfee security firm, users are reminded that the scanning of compressed files (default option) is required for detection.
Users can also detect and disinfect this and other malicious code using the free online antivirus Panda ActiveScan.
Still according to the antivirus maker, if the date check is satisfied, the virus executes the standard Windows Sound Recorder (SNDREC32.EXE) application. The virus uses the same icon as this application and copies itself into the Windows system directory as AU.EXE.
The following Registry key is added to hook system startup:
Run "au.exe" = C:\WINNT\SYSTEM32\AU.EXE
Additionally, the following two Registry keys are added:
The virus constructs messages using its own SMTP engine. Target email addresses are harvested from files with the following extensions on the victim machine:
The virus spoofs the sender address by using a harvested address in the From: field, using the following e-mail structure:
From : (address is spoofed) Subject : ID (string)... thanks Body :
Yours ID (string2)
The e-mail will contain an attachment randomly named of 11,264 bytes with .EXE file extension.
A notification is sent to the author(s) via HTTP. A GET request (containing the port number and "id") is sent to a PHP script on remote server(s). Users are recommended to block access to the following domains:
This worm is also known with other names: W32.Alua@mm, Win32/Bagle.B.Worm [Computer Associates], Bagle.B [F-Secure], W32/Bagle.b@MM [McAfee], W32/Bagle.B@mm [Norman], WORM_BAGLE.B [Trend Mirco], W32/Bagle.B.worm [Panda], W32/Tanx-A [Sophos].