Threat Descriptions

WebMoney trojan

Classification

Category :

Malware

Type :

Trojan

Platform :

W32

Aliases :

WebMoney trojan, TrojanDownloader.Win32.Small.n, Trojan.WebMoney.WMPatch

Summary

In the beginning of March 2003 there appeared the 3-component trojan that stole information from WebMoney users. WebMoney is the service that allows its users to transfer money anywhere in the world or to pay for goods in webshops. The creators of the trojan spread it in Russia first.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

The following message was sent to numerous people (the message was in both English and Russian): 

Hello!  You've got a postcard! To view this postcard, click on the link:  http://www.yahoo-greeting-cards.com/viewcards/mar/viewcard_.asp.scr  You will be able to see it at anytime within the next 60 days.  ____________________________________________________  Favorite postcards on http://www.yahoo-greeting-cards.com

Here's the screenshot of that message:

The link pointed to the small downloader program. When the downloader is run, it shows a fake error message: 

Hello!
You've got a postcard! To view this postcard, click on the link:
http://www.yahoo-greeting-cards.com/viewcards/mar/viewcard_.asp.scr
You will be able to see it at anytime within the next 60 days.
____________________________________________________
Favorite postcards on http://www.yahoo-greeting-cards.com

Then the downloader connects to Internet and downloads 2 files from the www.yahoo-greeting-cards.com website: 

Hello!
You've got a postcard! To view this postcard, click on the link:
http://www.yahoo-greeting-cards.com/viewcards/mar/viewcard_.asp.scr
You will be able to see it at anytime within the next 60 days.
____________________________________________________
Favorite postcards on http://www.yahoo-greeting-cards.com

These files are dropped to Windows System directory. The SICKBOY.EXE file is installed to system as SYSVIEW.EXE file. The downloader creates startup keys for the downloaded files in System Registry: 

Hello!
You've got a postcard! To view this postcard, click on the link:
http://www.yahoo-greeting-cards.com/viewcards/mar/viewcard_.asp.scr
You will be able to see it at anytime within the next 60 days.
____________________________________________________
Favorite postcards on http://www.yahoo-greeting-cards.com

where %winsysdir% represents Windows System directory. As a result, both files become active after next system restart.

The DBOLE.EXE file patches the WMClient.dll file (WebMoney software component) to intercept data from it. The DBOLE.EXE file is run only once - after successful patching, it modifies its startup key in the Registry to avoid starting itself next time.

The SYSVIEW.EXE file tries to locate 'WebmoneyKeeper' window and in case of a success, it sets a timer to 2 minutes. And every 2 minutes he trojan attempts to send the stolen information to <sickboy@centrum.cz> address. The trojan uses 62.84.131.172 mail server to send emails. The trojan attaches 3 files to the email message it was sending: 

Hello!
You've got a postcard! To view this postcard, click on the link:
http://www.yahoo-greeting-cards.com/viewcards/mar/viewcard_.asp.scr
You will be able to see it at anytime within the next 60 days.
____________________________________________________
Favorite postcards on http://www.yahoo-greeting-cards.com

The WMKEY and WMMEM files contain stolen data, the WMLOG file is a log file.

F-Secure detects all 3 trojan's files. The trojan downloader is detected as 'TrojanDownloader.Win32.Small.n' and main trojan files are detected as 'Trojan.WebMoney.WMPatch' with the following update:

Detection Type: PC

Database: 2003-03-05_02