Trojan.VBS.URV
Summary
Detections that use the naming format Trojan.VBS.[variant] identify VBS script files that download malware onto the user's machine.
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:
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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.
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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.
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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 VBS script files identified by a Trojan.VBS.[variant] detection are distributed as attachments to an email message. At the time of writing, this malware was most frequently reported in Germany, followed by Finland and France.
Delivered via email
For the VBS file analyzed (SHA1: 4eed6655966101b6c7c088d2d54289a77a1f89fe), the email message used to deliver it had the subject line RE:[recipient's username], while the email body is left empty.
Trojan.VBS.URV: Email message
Trojan.VBS.URV: Email file attachments
The VBS file itself was attached to the email as a ZIP file, and used a name with the following format: CONTRACT_[number]_ [username of the recipient].zip. The VBS file itself is named "contract.vbs".
If the user clicks on and opens the attached ZIP file, the VBS file is executed and tries to download an executable file named "contact.exe" from a remote server to the %temp% folder on the user's machine, then run the EXE.
Trojan.VBS.URV: Downloads payload from a remote server
Downloads ransomware
In the sample analyzed, the downloaded EXE file (SHA1:9001ede2a5cdaeb23762cc083f689334599981d2) is ransomware from the Cerber family.
If the EXE file is successfully run, it encrypts files stored on the machine and appends a ".cerber" extension at the end of filename. A payment is then demanded from the user to restore normal access to the affected files.
F-Secure identifies the ransomware separately with the Trojan:W32/Teslacrypt.E!DeepGuard detection.