TROJ_DROPPER.ZYI

July 15, 2014
 Analysis by: Al Victor de Leon
 ALIASES:

Backdoor.Win32.Hupigon.swza (Kaspersky), Trojan.Crypt, Trojan.Crypt (Ikarus), Trojan.Win32.Generic!BT (Sunbelt), Trojan horse Generic10_c.CMQB (AVG), W32/Hupigon.SWZA!tr.bdr, [demo.mp4]:W32/Hupigon.SWZA!tr.bdr (Fortinet)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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.

  TECHNICAL DETAILS

File Size:

3,458,420 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

12 Jun 2014

Payload:

Drops files

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 component file(s):

  • %Program Files%\Windows NT\demo.mp4 - detected as BKDR_HUPIGON.YAA
  • %Program Files%\Windows NT\urls.xml - detected as TROJ_CLIPAGENT.A
  • %Program Files%\Windows NT\InstallShield.xml - detected as TROJ_CLIPAGENT.A
  • %Program Files%\Windows NT\FreeJapanAV.exe - detected as TROJ_CLIPAGENT.A
  • %Program Files%\Windows NT\FreeJapanAV.ini

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\WinRAR SFX

It adds the following registry entries:

HKEY_CURRENT_USER\Software\WinRAR SFX
C%%Program Files%Windows NT% = "%Program Files%\Windows NT\"

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.856.07

FIRST VSAPI PATTERN DATE:

11 Jun 2014

VSAPI OPR PATTERN File:

10.857.00

VSAPI OPR PATTERN Date:

11 Jun 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Remove grayware/spyware files dropped/downloaded by TROJ_DROPPER.ZYI

     
    • BKDR_HUPIGON.YAA
    • TROJ_CLIPAGENT.A

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software
    • WinRAR SFX

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPER.ZYI. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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