TROJ_RANSOM.SMAL
Trojan Horse (Symantec); Trojan-Dropper.Win32.PMax.b (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Dropper.Generic.CHDA (AVG)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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.
TECHNICAL DETAILS
79,360 bytes
EXE
Yes
15 Apr 2013
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.
Autostart Technique
This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
Other System Modifications
This Trojan deletes the following files:
- \systemroot\win32k.sys
It adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Internet Explorer\Main\{F9197A7E-CE10-458e-85F8-5B0CE6DF2BBE}
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
ImagePath = "\systemroot\win32k.sys:2 "
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
Type = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
Start = "3"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
ImagePath = "\systemroot\win32k.sys:1 "
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
Type = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
Start = "3"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main\{F9197A7E-CE10-458e-85F8-5B0CE6DF2BBE}
Id = "623125312"
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
Dropping Routine
This Trojan drops the following files:
- \Device\__max++\systemroot
- \systemroot\system32\eventlog.dll
- %User Profile%\Documents\Thumbs.db
(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.)
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
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- {79007602-0CDB-4405-9DBF-1257BB3226EE}
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- {79007602-0CDB-4405-9DBF-1257BB3226ED}
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main
- {F9197A7E-CE10-458e-85F8-5B0CE6DF2BBE}
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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
- ImagePath = "\systemroot\win32k.sys:2 "
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
- Type = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
- Start = "3"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226EE}
- ErrorControl = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
- ImagePath = "\systemroot\win32k.sys:1 "
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
- Type = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
- Start = "3"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\{79007602-0CDB-4405-9DBF-1257BB3226ED}
- ErrorControl = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main\{F9197A7E-CE10-458e-85F8-5B0CE6DF2BBE}
- Id = "623125312"
Step 5
Search and delete these components
- \Device\__max++\systemroot
- \systemroot\system32\eventlog.dll
- %User Profile%\Documents\Thumbs.db
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_RANSOM.SMAL. 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 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.
- \systemroot\win32k.sys
Step 8
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\SYSTEM\ControlSet001\Services
- {79007602-0CDB-4405-9DBF-1257BB3226EE}
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services
- {79007602-0CDB-4405-9DBF-1257BB3226ED}
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