BKDR_POISON.BTT
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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
1,009,880 bytes
EXE
No
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.
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\WinRAR SFX
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\AppCompatFlags\
Layers
It adds the following registry entries:
HKEY_CURRENT_USER\Software\WinRAR SFX
C%%WINDOWS%system32 = "%System%"
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\AppCompatFlags\
Layers
%System%\crypt.exe = "~ RUNASADMIN"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\MD ServicesB1
Description = "Thank you"
Dropping Routine
This backdoor drops the following files:
- __tmp_rar_sfx_access_check_60468
- crypt.exe
- adminreg.reg
- admin.vbs
- %Program Files%\Internet Explorer\Svcwtyh.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).)
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
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
- WinRAR SFX
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags
- Layers
Step 3
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\WinRAR SFX
- C%%WINDOWS%system32 = "%System%"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
- %System%\crypt.exe = "~ RUNASADMIN"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\MD ServicesB1
- Description = "Thank you"
Step 4
Search and delete these components
- __tmp_rar_sfx_access_check_60468
- crypt.exe
- adminreg.reg
- admin.vbs
- %Program Files%\Internet Explorer\Svcwtyh.exe
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_POISON.BTT. 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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