TROJ_REDOS.SME
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 deletes registry entries, causing some applications and programs to not function properly.
TECHNICAL DETAILS
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 adds the following folders:
- %Program Files%\%SESSIONNAME%
It drops the following component file(s):
- %Program Files%\%SESSIONNAME%\{random characters}.cc3
- %System%\{random characters}.rdb
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other System Modifications
This Trojan adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Comhidserv70\Parameters
seRVicemAIN = "NPGetResourceParent"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Comhidserv70\Parameters
seRVicedlL = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ\Parameters
seRVicemAIN = "NPGetResourceParent"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
ErrorControl = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ\Parameters
ServiceDll = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
(Note: The default value data of the said registry entry is %System%\hidserv.dll.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
Start = "2"
(Note: The default value data of the said registry entry is 4.)
It deletes the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
DependOnService = "RpcSs"
SOLUTION
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 terminate files detected as TROJ_REDOS.SME
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 3
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
- From: ErrorControl = "0"
To: ErrorControl = "1"
- From: ErrorControl = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ\Parameters
- From: ServiceDll = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
To: ServiceDll = "%System%\hidserv.dll"
- From: ServiceDll = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
- From: Start = "2"
To: Start = "4"
- From: Start = "2"
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\SOFTWARE\Microsoft\Comhidserv70\Parameters
- seRVicemAIN = "NPGetResourceParent"
- seRVicemAIN = "NPGetResourceParent"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Comhidserv70\Parameters
- seRVicedlL = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
- seRVicedlL = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ\Parameters
- seRVicemAIN = "NPGetResourceParent"
- seRVicemAIN = "NPGetResourceParent"
Step 5
Search and delete this file
- %System%\{random characters}.rdb
Step 6
Search and delete this folder
- %Program Files%\%SESSIONNAME%
Step 7
Scan your computer with your Trend Micro product to delete files detected as TROJ_REDOS.SME. 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 this deleted registry key/value 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\CurrentControlSet\Services\HidServ
- DependOnService = "RpcSs"
- DependOnService = "RpcSs"
Did this description help? Tell us how we did.