WORM_MYTOB.BT
Worm:Win32/Mytob.W@mm (Microsoft); W32/Mytob.gen@MM (McAfee); W32.Mytob.AH@mm (Symantec); Net-Worm.Win32.Mytob.t (Kaspersky); Trojan.Win32.Ircbot!cobra (v) (Sunbelt); I-Worm/Mytob.BD (AVG)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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
80,896 bytes
EXE
Yes
15 May 2013
Arrival Details
This worm 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 worm drops the following copies of itself into the affected system:
- %System%\taskgmr.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WINRUN = "taskgmr.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
WINRUN = "taskgmr.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
WINRUN = "taskgmr.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MSMSGS = "%Program Files%\Messenger\msmsgs.exe /background"
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
HKEY_CURRENT_USER\Software\Microsoft\
OLE
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Control\Lsa
HKEY_CURRENT_USER\AppEvents\Schemes\
Apps\MSMsgs\MSMsgs_ContactOnline\
.Default
HKEY_CURRENT_USER\AppEvents\Schemes\
Apps\MSMsgs\MSMsgs_NewAlert\
.Default
HKEY_CURRENT_USER\AppEvents\Schemes\
Apps\MSMsgs\MSMsgs_NewMail\
.Default
HKEY_CURRENT_USER\AppEvents\Schemes\
Apps\MSMsgs\MSMsgs_NewMessage\
.Default
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
OLE
WINRUN = "taskgmr.exe"
HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Control\Lsa
WINRUN = "taskgmr.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Ole
WINRUN = "taskgmr.exe"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
WINRUN = "taskgmr.exe"
Dropping Routine
This worm drops the following files:
- %System Root%\hellmsn.exe
- %System Root%\funny_pic.scr
- %System Root%\see_this!!.scr
- %System Root%\my_photo2005.scr
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
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\SOFTWARE\Microsoft\Windows\CurrentVersion
- RunServices
- In HKEY_CURRENT_USER\Software\Microsoft
- OLE
- In HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\Control
- Lsa
- In HKEY_CURRENT_USER\AppEvents\Schemes\Apps\MSMsgs\MSMsgs_ContactOnline
- .Default
- In HKEY_CURRENT_USER\AppEvents\Schemes\Apps\MSMsgs\MSMsgs_NewAlert
- .Default
- In HKEY_CURRENT_USER\AppEvents\Schemes\Apps\MSMsgs\MSMsgs_NewMail
- .Default
- In HKEY_CURRENT_USER\AppEvents\Schemes\Apps\MSMsgs\MSMsgs_NewMessage
- .Default
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\Windows\CurrentVersion\Run
- WINRUN = "taskgmr.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
- WINRUN = "taskgmr.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- WINRUN = "taskgmr.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- MSMSGS = "%Program Files%\Messenger\msmsgs.exe /background"
- In HKEY_CURRENT_USER\Software\Microsoft\OLE
- WINRUN = "taskgmr.exe"
- In HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\Control\Lsa
- WINRUN = "taskgmr.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
- WINRUN = "taskgmr.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
- WINRUN = "taskgmr.exe"
Step 5
Search and delete these components
- %System Root%\hellmsn.exe
- %System Root%\funny_pic.scr
- %System Root%\see_this!!.scr
- %System Root%\my_photo2005.scr
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_MYTOB.BT. 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.
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