BKDR_MSPOSER.B
Windows 2000, Windows XP, Windows Server 2003
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
1,260,032 bytes
EXE
Yes
06 Sep 2013
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 drops the following copies of itself into the affected system:
- %Program Files%\MSUpdate\MSupdate.exe
(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).)
It creates the following folders:
- %User Profile%\Application Data\DYA_ATANJTHOHJSWUMGQC
- %User Profile%\DYA_ATANJTHOHJSWUMGQC\1.0.0
- %User Profile%\1.0.0\Data
- %Program Files%\MSUpdate
- %User Temp%\dclogs
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} 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).. %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.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MSUpdate = "%Program Files%\MSUpdate\MSupdate.exe"
It modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
UserInit = "%System%\userinit.exe,%Program Files%\MSUpdate\MSupdate.exe"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\DC3_FEXEC
Dropping Routine
This backdoor drops the following files:
- %User Profile%\Data\app.dat
- %User Profile%\Data\updates.dat
- %User Profile%\Data\dya.dat
- %User Profile%\Application Data:$SS_DESCRIPTOR_SBXNV9VVGV1BFSVHKV1EB96JMXL64NJ40J0W0WJFSVF7VB4VP4GF
- %User Profile%\DYA_ATANJTHOHJSWUMGQC\1.0.0:$SS_DESCRIPTOR_SBXNV9VVGV1BFSVHKV1EB96JMXL64NJ40J0W0WJFSVF7VB4VP4GF
- %Desktop%:$SS_DESCRIPTOR_SBXNV9VVGV1BFSVHKV1EB96JMXL64NJ40J0W0WJFSVF7VB4VP4GF
- %User Temp%\FUNSDOTAHACK_1.4.EXE
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista and 7.. %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.)
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Identify and delete files detected as BKDR_MSPOSER.B using either the Startup Disk or Recovery Console
Step 3
Delete this registry key
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
- DC3_FEXEC
Step 4
Delete this registry value
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\Microsoft\Windows\CurrentVersion\Run
- MSUpdate = "%Program Files%\MSUpdate\MSupdate.exe"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: UserInit = "%System%\userinit.exe,%Program Files%\MSUpdate\MSupdate.exe"
To: UserInit = ""%Windows%\system32\userinit.exe,""
- From: UserInit = "%System%\userinit.exe,%Program Files%\MSUpdate\MSupdate.exe"
Step 6
Search and delete these components
- %User Profile%\Data\app.dat
- %User Profile%\Data\updates.dat
- %User Profile%\Data\dya.dat
- %User Profile%\Application Data:$SS_DESCRIPTOR_SBXNV9VVGV1BFSVHKV1EB96JMXL64NJ40J0W0WJFSVF7VB4VP4GF
- %User Profile%\DYA_ATANJTHOHJSWUMGQC\1.0.0:$SS_DESCRIPTOR_SBXNV9VVGV1BFSVHKV1EB96JMXL64NJ40J0W0WJFSVF7VB4VP4GF
- %Desktop%:$SS_DESCRIPTOR_SBXNV9VVGV1BFSVHKV1EB96JMXL64NJ40J0W0WJFSVF7VB4VP4GF
- %User Temp%\FUNSDOTAHACK_1.4.EXE
Step 7
Search and delete these folders
- %User Profile%\Application Data\DYA_ATANJTHOHJSWUMGQC
- %User Profile%\DYA_ATANJTHOHJSWUMGQC\1.0.0
- %User Profile%\1.0.0\Data
- %Program Files%\MSUpdate
- %User Temp%\dclogs
Step 8
Scan your computer with your Trend Micro product to delete files detected as BKDR_MSPOSER.B. 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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