TROJ_REGRUN.USAV0109
[000ea00c.EXE]:Generic.dx!bcj4 (McAfee); Trojan Horse (Symantec); PAK:Armadillo, Trojan.Win32.Agent.bhom (Kaspersky); Trojan.Generic.2533157 (FSecure)
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
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\TEMP
(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.)
Other System Modifications
This Trojan adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Licenses
HKEY_CLASSES_ROOT\CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}\InprocServer32
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{R7C0DB872A3F777C0} = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{K7C0DB872A3F777C0} = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{IC6E3D0636B8B23B2} = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
{0C6E3D0636B8B23B2} = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\advapi32.dll[MofResourceName] = "{random characters}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "{random characters}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\mssmbios.sys[MofResource] = "{random characters}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "{random characters}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ipnat.sys[IPNATMofResource] = "{random characters}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\Drivers\HTTP.sys[UlMofResource] = "{random characters}"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent\CurrentVersion\Parameters
TrapPollTimeMilliSecs = "3a98"
(Note: The default value data of the said registry entry is 3a98.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}\Version
This report is generated via an automated analysis system.
SOLUTION
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_LOCAL_MACHINE\Software
- Licenses
- In HKEY_CLASSES_ROOT\CLSID
- {AAC09E81-936B-7F4F-3256-424B5DA0856B}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}
- InprocServer32
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_LOCAL_MACHINE\SOFTWARE\Licenses
- {R7C0DB872A3F777C0} = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
- {K7C0DB872A3F777C0} = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
- {IC6E3D0636B8B23B2} = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Licenses
- {0C6E3D0636B8B23B2} = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- %System%\advapi32.dll[MofResourceName] = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- %System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- %System%\DRIVERS\mssmbios.sys[MofResource] = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- %System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- %System%\DRIVERS\ipnat.sys[IPNATMofResource] = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- %System%\Drivers\HTTP.sys[UlMofResource] = "{random characters}"
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_LOCAL_MACHINE\SOFTWARE\Microsoft\RFC1156Agent\CurrentVersion\Parameters
- From: TrapPollTimeMilliSecs = "3a98"
To: TrapPollTimeMilliSecs = ""3a98""
- From: TrapPollTimeMilliSecs = "3a98"
Step 5
Search and delete this folder
- %User Profile%\Application Data\TEMP
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_REGRUN.USAV0109. 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 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\Classes\CLSID\{AAC09E81-936B-7F4F-3256-424B5DA0856B}
- Version
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