Document with VBA Macro drops a variety of malware

January 15, 2016

The Dell Sonicwall Threats Research team has received reports of a Microsoft Word document file containing a malicious VBA script. This dropper Trojan has been around for a while in various different forms and drops malware from a variety of different families.

Infection Cycle:

The Trojan arrives as a MS Word Document file:

Quick analysis of the doc file shows the presence of a VBA macro and references to a remote webserver containing an executable file:

Once opened, the following document is shown in MS Word:

The document encourages the user to enable the malicious macro as the document has “incorrect encoding”. Once the macro is executed it causes the download of a malicious executable file:

The Trojan adds the following files to the filesystem:

  • %USERPROFILE%Local SettingsTemppcampaniliformgoodfellow.exe [Detected as GAV: Upatre.JO (Trojan)]

The file downloaded in the case was a variant of the Upatre Trojan. It exhibits the usual encrypted traffic:

It has been reported by other vendors that variants of this Word Document also drop malicious files from other malware families.

SonicWALL Gateway AntiVirus provides protection against this threat via the following signatures:

  • GAV: Upatre.JO (Trojan)
  • GAV: Downloader.ANZ (Trojan)