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Win32.Frethem.J@mm

HIGH

VERY LOW

48 Kbytes

(I-Worm.Frethem, W32/Frethem.l@MM, WORM_FRETHEM.K)

Symptoms

File setup.exe in the StartUp folder (usually in C:\Windows\Start Menu\Programs\StartUp or in %USERPROFILE%\Start Menu Programs\StartUp);

File taskbar.exe in the Windows directory (usuallyC:\Windows or C:\Winnt).

Removal instructions:

The BitDefender Virus Analyse Team has releasead a free removal tool for this particular virus.

Important: You will have to close all applications before running the tool (including the antivirus shields) and to restart the computer afterwards. Additionally you'll have to manually delete the infected files located in archives and the infected messages from your mail client.

The BitDefender AntiFrethem tool does the following:

it detects all the known Win32.Frethem versions;

it deletes the files infected with Win32.Frethem;

it kills the process from memory;

it repairs the Windows registry.

To prevent the virus from replicating itself from infected machines to clean machines, you should try to disinfect all computers in the network before rebooting any of them, or unplug the network cables.

If you are running Windows 95/98/Me you will have to apply the following patch provided by Microsoft to stop the virus from using the "Share Level Password" Vulnerability.

You may also need to restore the affected files.

Analyzed By

Costin Ionescu BitDefender Virus Researcher

Technical Description:

This is a new version of Win32.Frethem.F@mm. The virus spreads through e-mail as an attached file.

The format of an infected e-mail is (the same as in the previous versions):

From:
Subject: Re: Your password!
Body:
ATTENTION!
You can access very important information by this password
DO NOT SAVE password to disk use your mind
now press cancel

Attachments: decrypt-password.exe, password.txt.

The e-mail also contains the IFRAME vulnerability (described by Microsoft at http://www.microsoft.com/technet/security/bulletin/MS01-020.asp) so if the user reads his e-mail with an unpatched version of Microsoft Outlook or Microsoft Outlook Express, it will be infected when it views the message in the preview pane.

The virus copies itself as setup.exe in the Startup directory of the current profile (as shown in the Symptoms section) and in Windows directory as taskbar.exe. Also it writes in the key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

the value Task Bar to point to the taskbar.exe file.

It uses the SMTP servers of the victim and the e-mails stored in Windows Address Book (used by Outlook Express) and in all DBX, WAB, MBX, EML, MDB, DAT files from disk to send infected e-mails. Also e-mail addresses are searched in all files from subfolders called mail or imapmail.

The author wrote in the executable:
ThAnks tO AUthOr! YOU ArE rEAllY grEAt mAn!
AlsO thAnks tO AntIvIrUs cOmpAnIEs fOr dEscrIbIng thE mAIlEr IdEA!
nO AnY dEstrUctIvE ActIOns! dOnt wArrY, bE hAppY!

As its previous versions it does not infect computers which have installed the keybord layouts specific for Russian and Uzbek keyboards.