TROJ_AGENT.BCTW
TrojanDownloader:Win32/Kuluoz.B (Microsoft); PAK:UPX (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
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.
It modifies files, disabling programs and applications from properly running.
TECHNICAL DETAILS
57,344 bytes
EXE
Yes
19 Jun 2012
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 creates the following folders:
- %User Profile%\Application Data\529C50B4000DF75B69ACEAAD2830AC72
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
tufahllm = "%Application Data%\fcccedwl.exe"
Other System Modifications
This Trojan modifies the following files:
- %User Profile%\Application Data\Microsoft
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\cnmdclpu
HKEY_CURRENT_USER\Software\tyfbjm
HKEY_CURRENT_USER\Software\Microsoft\
Sft
It adds the following registry entries:
HKEY_CURRENT_USER\Software\cnmdclpu
injcsetq = "E637CC0CE069C958E03F9D58E437CB5DD00FAD68"
HKEY_CURRENT_USER\Software\cnmdclpu
injcsetq = "E637CC0CE069C958E03F9D58E437CB5DA36BC104ED6ACC0EA66DDC0FB234AD68"
HKEY_CURRENT_USER\Software\tyfbjm
qsgrwg = "{random values}"
Dropping Routine
This Trojan drops the following files:
- .txt
- %Application Data%\dkdpocwx.exe
- %Application Data%\eqpbiwaa.exe
- %Application Data%\tbhfhipf.exe
- %Application Data%\poovncke.exe
- %Application Data%\rfsqgwjb.exe
- %Application Data%\eafvbqgb
- %User Profile%\529C50B4000DF75B69ACEAAD2830AC72\529C50B4000DF75B69ACEAAD2830AC72
- %User Profile%\529C50B4000DF75B69ACEAAD2830AC72\529C50B4000DF75B69ACEAAD2830AC72.exe
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\RSA
- %User Profile%\RSA\S-1-5-21-1645522239-1292428093-682003330-1003
- %User Temp%\knrbvcvw.zip
- %User Temp%\doc115.txt
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://www.{BLOCKED}s.ch/images/3.exe
- http://www.{BLOCKED}su.com/images/3.exe
- http://www.{BLOCKED}avicini.com/images/_vti_cnf/3.exe
- http://{BLOCKED}korea.com/img/area/3.exe
- http://www.{BLOCKED}ta.hu/image/3.exe
- http://{BLOCKED}g.com/afyu/index.php?{random characters}
- http://{BLOCKED}r.com/nygul/index.php?{random characters}
- http://{BLOCKED}lands2012.ru/forum/index.php?{random characters}
- http://{BLOCKED}lands2012.ru/forum/get/php.dll.crp
- http://{BLOCKED}lands2012.ru/forum/get/p3.dll.crp
- http://{BLOCKED}lands2012.ru/forum/get/f3.dll.crp
- http://{BLOCKED}lands2012.ru/forum/get/svc.dll.crp
- http://{BLOCKED}5.235.9/api/urls/?ts=9ab8943a&affid=41100
- http://{BLOCKED}5.235.9/api/stats/install/?{random characters}
- http://{BLOCKED}lands2012.ru/forum/index.php?r=gate/dcheck
- http://bcspromo.{BLOCKED}o.uk/index.php?{random characters}
- http://niehoff.{BLOCKED}o.uk/index.php?{random characters}
- http://whlane.{BLOCKED}o.uk/index.php?{random characters}
- http://northbound.{BLOCKED}o.uk/index.php?{random characters}
- http://{BLOCKED}place.com/index.php?{random characters}
- http://c-t-s.{BLOCKED}k.com/index.php?{random characters}
- http://{BLOCKED}{BLOCKED}.net/index.php?{random characters}
This report is generated via an automated analysis system.
SOLUTION
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
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
- cnmdclpu
- In HKEY_CURRENT_USER\Software
- tyfbjm
- In HKEY_CURRENT_USER\Software\Microsoft
- Sft
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
- tufahllm = "%Application Data%\fcccedwl.exe"
- In HKEY_CURRENT_USER\Software\cnmdclpu
- injcsetq = "E637CC0CE069C958E03F9D58E437CB5DD00FAD68"
- In HKEY_CURRENT_USER\Software\cnmdclpu
- injcsetq = "E637CC0CE069C958E03F9D58E437CB5DA36BC104ED6ACC0EA66DDC0FB234AD68"
- In HKEY_CURRENT_USER\Software\tyfbjm
- qsgrwg = "{random values}"
Step 5
Search and delete these files
- .txt
- %Application Data%\dkdpocwx.exe
- %Application Data%\eqpbiwaa.exe
- %Application Data%\tbhfhipf.exe
- %Application Data%\poovncke.exe
- %Application Data%\rfsqgwjb.exe
- %Application Data%\eafvbqgb
- %User Profile%\529C50B4000DF75B69ACEAAD2830AC72\529C50B4000DF75B69ACEAAD2830AC72
- %User Profile%\529C50B4000DF75B69ACEAAD2830AC72\529C50B4000DF75B69ACEAAD2830AC72.exe
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\RSA
- %User Profile%\RSA\S-1-5-21-1645522239-1292428093-682003330-1003
- %User Temp%\knrbvcvw.zip
- %User Temp%\doc115.txt
Step 6
Search and delete this folder
- %User Profile%\Application Data\529C50B4000DF75B69ACEAAD2830AC72
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_AGENT.BCTW. 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.
Step 8
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %User Profile%\Application Data\Microsoft
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