TROJ_UPATRE.YUYBF

 Modified by: Sammy Chua

 ALIASES:

TrojanDownloader:Win32/Upatre (Microsoft); Trojan-Downloader.Win32.Upatre.fct (Kaspersky); Downloader.Upatre (Symantec)

 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 on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

26,624 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

03 Mar 2015

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\homeupd.exe

(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.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\{random}.exe - it executes this file

(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 connects to the following possibly malicious URL:

  • http://checkip.{BLOCKED}s.org/
  • http://{BLOCKED}lentino.com/WOW/data1/tooltips/gb_eulf.pdf
  • http://{BLOCKED}.{BLOCKED}.236.251:{random port}/1902us22/{Hostname}/0/{OS VERSION}/0/{Data}
  • http://{BLOCKED}.{BLOCKED}.236.251:{random port}/1902us22/{Hostname}/41/7/4/

It deletes the initially executed copy of itself