TROJ_ZEGOST.IQ

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

Trojan:Win32/Meredrop (Microsoft), multiple threats, Win32/Farfli.XB trojan, Win32/TrojanDropper.Autoit.BO trojan (ESET)

 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:

  • 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.

  TECHNICAL DETAILS

File Size:

1,466,424 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

13 Apr 2013

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 files:

  • %Current%\ccsbb.p7b
  • %Current%\check.exe - also detected as TROJ_ZEGOST.IQ
  • %Windows%\Installer\{random number}.msi
  • %Windows%\Installer\{709599CB-4CDD-447D-825E-9D5D3EDD4325}\_.exe
  • %User Temp%\新建文件夹 (2)\bankrun.exe
  • %Application Data%\中华人民共和國最高人民检察院\安全插件\bdardrv.dll
  • %Application Data%\中华人民共和國最高人民检察院\安全插件\bdcore.dll
  • %Application Data%\中华人民共和國最高人民检察院\安全插件\CrashReport.dll

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It creates the following folders:

  • %Windows%\Installer\{709599CB-4CDD-447D-825E-9D5D3EDD4325}
  • %User Temp%\新建文件夹 (2)
  • %Application Data%\中华人民共和國最高人民检察院
  • %Application Data%\中华人民共和國最高人民检察院\安全插件

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\中华人民共和國最高人民检察院

HKEY_CLASSES_ROOT\Installer\Components\
6C1AB6DD283548F42B136B93C8681BB3

HKEY_CLASSES_ROOT\Installer\Components\
F0F1729FDFB0F604FB3061A694E0840B

HKEY_CLASSES_ROOT\Installer\Features\
BC995907DDC4D74428E5D9D5E3DD3452

HKEY_CLASSES_ROOT\Installer\Products\
BC995907DDC4D74428E5D9D5E3DD3452

HKEY_CLASSES_ROOT\Installer\UpgradeCodes\
34A016B5C9E3B9E43975A658053A01A2

Other Details

This Trojan adds the following lines or registry entries as part of its routine:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\Folders
  • %Application Data%\中华人民共和國最高人民检察院\ 安全插件 = ""
  • %Windows%\Installer\{709599CB-4CDD-447D-825E-9D5D3EDD4325} = ""
  • HKEY_CLASSES_ROOT\Installer\Components\6C1AB6DD283548F42B136B93C8681BB3
  • 限定符字符串 = "=rb3Ljj'$=YBN*FWR&}.>"
  • HKEY_CLASSES_ROOT\Installer\Components\F0F1729FDFB0F604FB3061A694E0840B
  • 限定符字符串 = "=rb3Ljj'$=YBN*FWR&}.>"
  • HKEY_CLASSES_ROOT\Installer\Features\BC995907DDC4D74428E5D9D5E3DD3452
  • MainFeature = ""
  • HKEY_CLASSES_ROOT\Installer\Products\BC995907DDC4D74428E5D9D5E3DD3452
  • ProductName = "安全插件"
  • PackageCode = "D52C326865EFCEB44BFDF9DB82C3E262"
  • Language = "804"
  • Version = "1000000"
  • Assignment = "1"
  • AdvertiseFlags = "184"
  • ProductIcon = "%Windows%\Installer\{709599CB-4CDD-447D-825E-9D5D3EDD4325}\_.exe"
  • InstanceType = "0"
  • AuthorizedLUAApp = "0"
  • DeploymentFlags = "3"
  • Clients = ":"
  • HKEY_CLASSES_ROOT\Installer\UpgradeCodes\34A016B5C9E3B9E43975A658053A01A2
  • BC995907DDC4D74428E5D9D5E3DD3452 = ""

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %Windows% is the Windows folder, which is usually C:\Windows.)

It connects to the following possibly malicious URL:

  • http://www.download{BLOCKED}date.com/msdownload/update/v3/static/trustedr/en/authrootseq.txt
  • http://www.download{BLOCKED}date.com/msdownload/update/v3/static/trustedr/en/authrootstl.cab

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.858.03

FIRST VSAPI PATTERN DATE:

15 Apr 2013

VSAPI OPR PATTERN File:

9.859.00

VSAPI OPR PATTERN Date:

16 Apr 2013

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

Scan your computer with your Trend Micro product and note files detected as TROJ_ZEGOST.IQ

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_LOCAL_MACHINE\SOFTWARE
    •  中华人民共和國最高人民检察院
  • In HKEY_CLASSES_ROOT\Installer\Components
    • 6C1AB6DD283548F42B136B93C8681BB3
  • In HKEY_CLASSES_ROOT\Installer\Components
    • F0F1729FDFB0F604FB3061A694E0840B
  • In HKEY_CLASSES_ROOT\Installer\Features
    • BC995907DDC4D74428E5D9D5E3DD3452
  • In HKEY_CLASSES_ROOT\Installer\Products
    • BC995907DDC4D74428E5D9D5E3DD3452
  • In HKEY_CLASSES_ROOT\Installer\UpgradeCodes
    • 34A016B5C9E3B9E43975A658053A01A2

Step 4

Delete this registry value

[ 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\Folders
    • %Application Data%\中华人民共和國最高人民检察院\安全插件 = ""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\Folders
    • %Windows%\Installer\{709599CB-4CDD-447D-825E-9D5D3EDD4325} = ""

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Windows%\Installer\{709599CB-4CDD-447D-825E-9D5D3EDD4325}
  • %User Temp%\新建文件夹 (2)
  • %Application Data%\中华人民共和國最高人民检察院

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_ZEGOST.IQ. 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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