BKDR_HUPIGO.GDM


 ALIASES:

Trojan.Win32.Generic.pak!cobra (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor 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:

262,824 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

25 Apr 2012

Arrival Details

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

Autostart Technique

This backdoor registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinSock2\mswsock32

Other System Modifications

This backdoor adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\mswsock32
1001 = "%SystemRoot%\system32\mswsock.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\mswsock32
1002 = "%SystemRoot%\system32\mswsock.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\mswsock32
1003 = "%SystemRoot%\system32\mswsock.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\mswsock32
1004 = "%SystemRoot%\system32\rsvpsp.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\mswsock32
1005 = "%SystemRoot%\system32\rsvpsp.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\mswsock32
PathName = "%Program Files%\Common Files\Microsoft Shared\MSINFO\msinfo.dll"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\Parameters\
Protocol_Catalog9\Catalog_Entries\000000000001
PackedCatalogItem = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\Parameters\
Protocol_Catalog9\Catalog_Entries\000000000002
PackedCatalogItem = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\Parameters\
Protocol_Catalog9\Catalog_Entries\000000000003
PackedCatalogItem = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\Parameters\
Protocol_Catalog9\Catalog_Entries\000000000004
PackedCatalogItem = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\WinSock2\Parameters\
Protocol_Catalog9\Catalog_Entries\000000000005
PackedCatalogItem = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This backdoor drops the following files:

  • %Program Files%\Common Files\c_20870.nls
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\c_20870.nls
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\msinfo.dll

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Restart in Safe Mode

[ Learn More ]

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\SYSTEM\CurrentControlSet\Services\WinSock2
    • mswsock32

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\SYSTEM\ControlSet001\Services\WinSock2\mswsock32
    • 1001 = "%SystemRoot%\system32\mswsock.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\mswsock32
    • 1002 = "%SystemRoot%\system32\mswsock.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\mswsock32
    • 1003 = "%SystemRoot%\system32\mswsock.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\mswsock32
    • 1004 = "%SystemRoot%\system32\rsvpsp.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\mswsock32
    • 1005 = "%SystemRoot%\system32\rsvpsp.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\mswsock32
    • PathName = "%Program Files%\Common Files\Microsoft Shared\MSINFO\msinfo.dll"

Step 5

Restore this modified 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\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000001
    • From: PackedCatalogItem = "{random values}"
      To: PackedCatalogItem = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000002
    • From: PackedCatalogItem = "{random values}"
      To: PackedCatalogItem = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000003
    • From: PackedCatalogItem = "{random values}"
      To: PackedCatalogItem = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000004
    • From: PackedCatalogItem = "{random values}"
      To: PackedCatalogItem = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000005
    • From: PackedCatalogItem = "{random values}"
      To: PackedCatalogItem = ""{random values}""

Step 6

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Program Files%\Common Files\c_20870.nls
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\c_20870.nls
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\msinfo.dll

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_HUPIGO.GDM. 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.


Did this description help? Tell us how we did.