PDF_DOCDROP.YYSZS

May 19, 2017
 Analysis by: Joselyn Canuela
 ALIASES:

Trojan.PDF.Agent.CW (BitDefender), Trojan-Dropper:JS/PdfDropper.A (F-Secure), Trojan-Downloader.VBA.Agent (Ikarus), TrojanDownloader:O97M/Donoff!rfn (Microsoft)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives as an attachment to email messages mass-mailed by other malware/grayware or malicious users.

  TECHNICAL DETAILS

File Size:

64,575 bytes

File Type:

PDF

Initial Samples Received Date:

11 May 2017

Arrival Details

This Trojan arrives as an attachment to email messages mass-mailed by other malware/grayware or malicious users.

Installation

This Trojan drops the following files:

  • %User Temp%\A9R{4 random characters}.tmp\ET3W5YZHV.docm - contains macro

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It creates the following folders:

  • %User Temp%\A9R{4 random characters}.tmp

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This Trojan does the following:

  • It deletes the created folder and drop file once PDF file has been closed.