Analysis by: RonJay Kristoffer Caragay
ALIASES:

TrojanDownloader:Win32/Carberp.R (Microsoft); Backdoor.Win32.Symmi.rph (Kaspersky)

 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: 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: 77,589 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Aug 2014

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.

Installation

This backdoor adds the following folders:

  • %Program Files%\NVIDIA Corporation\Update Center
  • %User Temp%\ns{random}.tmp

(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).. %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.)

It drops the following files:

  • %User Temp%\ns{random}.tmp\System.dll
  • %Program Files%\NVIDIA Corporation\Update Center\nvdupdate.exe

(Note: %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.. %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 backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv

HKEY_USERS\.DEFAULT\Software\
NVIDIA Corporation

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv
Type = "16"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv
ImagePath = "%Program Files%\NVIDIA Corporation\Update Center\nv_update.exe /svc"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv
DisplayName = "NVIDIA Update Server"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NvUpdSrv
Description = "NVIDIA Settings Update Manager service, used to check new updates from NVIDIA server"

HKEY_USERS\.DEFAULT\Software\
NVIDIA Corporation\Global\nvUpdSrv
value = "{date}"

HKEY_USERS\.DEFAULT\Software\
NVIDIA Corporation\Global\nvUpdSrv
GUID = "{GUID}"

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}2.146.68
  • {BLOCKED}.{BLOCKED}78.62.114
  • {BLOCKED}.{BLOCKED}8.5.4
  • {BLOCKED}.{BLOCKED}3.165.27
  • {BLOCKED}.{BLOCKED}53.145.93
  • {BLOCKED}.{BLOCKED}.16.196
  • {BLOCKED}.{BLOCKED}52.22.141
  • {BLOCKED}.{BLOCKED}.37.72
  • {BLOCKED}.{BLOCKED}53.145.10
  • {BLOCKED}.{BLOCKED}53.145.38
  • {BLOCKED}.{BLOCKED}25.69.79
  • {BLOCKED}.{BLOCKED}94.44.51
  • {BLOCKED}.{BLOCKED}94.44.49
  • {BLOCKED}.{BLOCKED}94.44.52
  • {BLOCKED}.{BLOCKED}.26.147
  • {BLOCKED}.{BLOCKED}.33.135
  • {BLOCKED}.{BLOCKED}43.144.69
  • {BLOCKED}.{BLOCKED}53.145.18
  • {BLOCKED}.{BLOCKED}53.145.51
  • {BLOCKED}.{BLOCKED}54.68.186
  • {BLOCKED}.{BLOCKED}.188.110
  • {BLOCKED}.{BLOCKED}53.145.27
  • {BLOCKED}.{BLOCKED}53.145.69
  • {BLOCKED}.{BLOCKED}.40.147
  • {BLOCKED}.{BLOCKED}.92.168
  • {BLOCKED}.{BLOCKED}53.145.75
  • {BLOCKED}.{BLOCKED}6.8.199
  • {BLOCKED}.{BLOCKED}53.145.77
  • {BLOCKED}.{BLOCKED}.37.88
  • {BLOCKED}.{BLOCKED}53.145.78
  • {BLOCKED}.{BLOCKED}2.21.31
  • {BLOCKED}.{BLOCKED}.188.126
  • {BLOCKED}.{BLOCKED}53.145.94
  • {BLOCKED}.{BLOCKED}78.40.234
  • {BLOCKED}.{BLOCKED}.92.184
  • {BLOCKED}.{BLOCKED}53.145.106
  • {BLOCKED}.{BLOCKED}.37.104
  • {BLOCKED}.{BLOCKED}.188.72
  • {BLOCKED}.{BLOCKED}4.244.136
  • {BLOCKED}.{BLOCKED}.92.152
  • {BLOCKED}.{BLOCKED}5.94.104
  • {BLOCKED}.{BLOCKED}6.8.167
  • {BLOCKED}.{BLOCKED}5.94.103
  • {BLOCKED}.{BLOCKED}.33.119
  • {BLOCKED}.{BLOCKED}5.94.105
  • {BLOCKED}.{BLOCKED}.143.230
  • {BLOCKED}.{BLOCKED}.92.136
  • {BLOCKED}.{BLOCKED}5.94.107
  • {BLOCKED}.{BLOCKED}5.94.108
  • {BLOCKED}.{BLOCKED}8.88.50

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.110.02
FIRST VSAPI PATTERN DATE: 26 Aug 2014
VSAPI OPR PATTERN File: 11.111.00
VSAPI OPR PATTERN Date: 26 Aug 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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Search and delete this folder

[ 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.
  • %Program Files%\NVIDIA Corporation\Update Center
  • %User Temp%\ns{random}.tmp

Step 4

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
    • NvUpdSrv
  • In HKEY_USERS\.DEFAULT\Software
    • NVIDIA Corporation

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_CARBERP.YUI. 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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