TROJ_FAM_000193a.TOMA
TrojanDownloader:Win32/Dluca.AO (Microsoft); Downloader-DC (McAfee); Adware.SafeSearch (Symantec); Trojan-Downloader.Win32.Dluca.ce (Kaspersky); Trojan-Downloader.Dluca (v) (Sunbelt); Trojan.Generic.206507 (FSecure)
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
188,416 bytes
EXE
No
30 Apr 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 drops the following copies of itself into the affected system:
- %Program Files%\common files\system\ms1src.exe
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
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 deletes the following files:
- %User Temp%\qdelwbi.tmp
- %System%\safesearch.exe
- %Program Files%\primesoft\safesearch\safesearch.exe
- %System%\_SafeSearch.dll
- %System%\SafeSearch.dll
- %Program Files%\common files\system\ms1src.exe:Zone.Identifier
- \ms1src_update.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.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
It deletes the following folders:
- %Program Files%\primesoft\safesearch
- %Program Files%\primesoft
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
It adds the following registry keys:
HKEY_CLASSES_ROOT\CLSID\{00000000-0000-0000-0000-000000000001}\
InprocServer32
HKEY_CURRENT_USER\Software\Program Data
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
HKEY_CURRENT_USER\Software\Program Info
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Program Data
SSET = "ECR#171A02951E83"
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
GetIDRetryCounter = "0"
HKEY_CURRENT_USER\Software\Program Info
ClientID = "{78aa8b3a-10e7-432b-a4a7-4f5624a8fac5}"
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
LastWNK = "4f9db344"
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
FlashID = "1227362"
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
DaytimeDocID = "-1"
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
DaytimeDocTime = "0"
HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
GetInfoRetryCounter = "0"
It modifies the following registry entries:
HKEY_CURRENT_USER\SessionInformation
ProgramCount = "1"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\SessionInformation
ProgramCount = "0"
(Note: The default value data of the said registry entry is 2.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\Currentversion\Uninstall\
SafeSearch
HKEY_CURRENT_USER\Software\Microsoft\
Windows\Currentversion\Uninstall\
SafeSearch
Dropping Routine
This Trojan drops the following files:
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\RSA
- %User Profile%\RSA\S-1-5-21-4025279379-4087772427-2915903831-500
- %User Profile%\RSA\MachineKeys
- %User Temp%\WK_1.tmp
- %User Temp%\WK_2.tmp
(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.. %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://w.{BLOCKED}ejtudlk-dfjkeid.com/wk/getclientid.wnk?{random characters}
- http://w.{BLOCKED}ejtudlk-dfjkeid.com/wk/getclientinfo.wnk?{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
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_CLASSES_ROOT\CLSID\{00000000-0000-0000-0000-000000000001}
- InprocServer32
- In HKEY_CURRENT_USER\Software
- Program Data
- In HKEY_CURRENT_USER\Software\InfoSoft
- qsearch
- In HKEY_CURRENT_USER\Software
- Program Info
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\Program Data
- SSET = "ECR#171A02951E83"
- In HKEY_CURRENT_USER\Software\InfoSoft\qsearch
- GetIDRetryCounter = "0"
- In HKEY_CURRENT_USER\Software\Program Info
- ClientID = "{78aa8b3a-10e7-432b-a4a7-4f5624a8fac5}"
- In HKEY_CURRENT_USER\Software\InfoSoft\qsearch
- LastWNK = "4f9db344"
- In HKEY_CURRENT_USER\Software\InfoSoft\qsearch
- FlashID = "1227362"
- In HKEY_CURRENT_USER\Software\InfoSoft\qsearch
- DaytimeDocID = "-1"
- In HKEY_CURRENT_USER\Software\InfoSoft\qsearch
- DaytimeDocTime = "0"
- In HKEY_CURRENT_USER\Software\InfoSoft\qsearch
- GetInfoRetryCounter = "0"
Step 4
Restore this modified 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\SessionInformation
- From: ProgramCount = "1"
To: ProgramCount = ""2""
- From: ProgramCount = "1"
- In HKEY_CURRENT_USER\SessionInformation
- From: ProgramCount = "0"
To: ProgramCount = ""2""
- From: ProgramCount = "0"
Step 5
Search and delete these files
- %User Profile%\Microsoft\Crypto
- %User Profile%\Crypto\RSA
- %User Profile%\RSA\S-1-5-21-4025279379-4087772427-2915903831-500
- %User Profile%\RSA\MachineKeys
- %User Temp%\WK_1.tmp
- %User Temp%\WK_2.tmp
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_FAM_000193a.TOMA. 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 7
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
Step 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\qdelwbi.tmp
- %System%\safesearch.exe
- %Program Files%\primesoft\safesearch\safesearch.exe
- %System%\_SafeSearch.dll
- %System%\SafeSearch.dll
- %Program Files%\common files\system\ms1src.exe:Zone.Identifier
- \ms1src_update.exe
Step 9
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Currentversion\Uninstall
- SafeSearch
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\Currentversion\Uninstall
- SafeSearch
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