WORM_OTORUN.BF
Worm:Win32/Tupym.A (Microsoft); W32/Tupym.worm (McAfee); W32.Svich (Symantec); Trojan.Win32.Patched.lx (Kaspersky); W32/AutoRun-BUC (Sophos); Trojan.Win32.AutoIT.gen (v) (Sunbelt); Trojan horse Generic32.AORF (AVG)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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
879,617 bytes
EXE
Yes
10 Sep 2014
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%\system3_.exe
- %Windows%\system3_.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Yahoo Messengger = "%System%\system3_.exe"
It modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "Explorer.exe system3_.exe"
(Note: The default value data of the said registry entry is Explorer.exe.)
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Internet Explorer\Control Panel
HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
WorkgroupCrawler\Shares
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Schedule
AtTaskMaxHours = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
WorkgroupCrawler\Shares
shared = "\New Folder.exe"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Page_URL = "http://www.{BLOCKED}mworld.50webs.com"
(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Search_URL = "http://www.{BLOCKED}mworld.50webs.com"
(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Search Page = "http://www.{BLOCKED}mworld.50webs.com"
(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}mworld.50webs.com"
(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home.)
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://www.{BLOCKED}mworld.50webs.com"
(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)
Dropping Routine
This worm drops the following files:
- d:\New Folder.exe
- d:\system3_.exe
- d:\autorun.inf
Other Details
This worm connects to the following possibly malicious URL:
- http://h1.{BLOCKED}y.com/asdb000/setting.ini
- http://h1.{BLOCKED}y.com/set/setting.ini
- http://h1.{BLOCKED}y.com/asdb002/setting.ini
- http://h1.{BLOCKED}y.com/asdb004/setting.ini
- http://h1.{BLOCKED}y.com/asdb006/setting.ini
- http://h1.{BLOCKED}y.com/asdb008/setting.ini
- http://h1.{BLOCKED}y.com/asdb010/setting.ini
- http://h1.{BLOCKED}y.com/asdb012/setting.ini
- http://h1.{BLOCKED}y.com/asdb014/setting.ini
- http://h1.{BLOCKED}y.com/asdb016/setting.ini
- http://h1.{BLOCKED}y.com/asdb018/setting.ini
- http://h1.{BLOCKED}y.com/asdb020/setting.ini
- http://h1.{BLOCKED}y.com/asdb022/setting.ini
- http://h1.{BLOCKED}y.com/asdb024/setting.ini
- http://h1.{BLOCKED}y.com/asdb026/setting.ini
- http://h1.{BLOCKED}y.com/asdb028/setting.ini
- http://h1.{BLOCKED}y.com/asdb030/setting.ini
- http://h1.{BLOCKED}y.com/asdb032/setting.ini
- http://h1.{BLOCKED}y.com/asdb034/setting.ini
- http://h1.{BLOCKED}y.com/asdb036/setting.ini
- http://h1.{BLOCKED}y.com/asdb038/setting.ini
- http://h1.{BLOCKED}y.com/asdb040/setting.ini
- http://h1.{BLOCKED}y.com/asdb042/setting.ini
- http://h1.{BLOCKED}y.com/asdb044/setting.ini
- http://h1.{BLOCKED}y.com/asdb046/setting.ini
- http://h1.{BLOCKED}y.com/asdb048/setting.ini
- http://h1.{BLOCKED}y.com/asdb050/setting.ini
- {BLOCKED}224.183
- {BLOCKED}.161.109
This report is generated via an automated analysis system.
SOLUTION
9.700
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 delete files detected as WORM_OTORUN.BF using either the Startup Disk or Recovery Console
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\Policies\Microsoft\Internet Explorer
- Control Panel
- In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer
- Control Panel
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\WorkgroupCrawler
- Shares
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Yahoo Messengger = "%System%\system3_.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Schedule
- AtTaskMaxHours = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\WorkgroupCrawler\Shares
- shared = "\New Folder.exe"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
- From: Default_Page_URL = "http://www.{BLOCKED}mworld.50webs.com"
To: Default_Page_URL = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome""
- From: Default_Page_URL = "http://www.{BLOCKED}mworld.50webs.com"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
- From: Default_Search_URL = "http://www.{BLOCKED}mworld.50webs.com"
To: Default_Search_URL = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch""
- From: Default_Search_URL = "http://www.{BLOCKED}mworld.50webs.com"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
- From: Search Page = "http://www.{BLOCKED}mworld.50webs.com"
To: Search Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch""
- From: Search Page = "http://www.{BLOCKED}mworld.50webs.com"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
- From: Start Page = "http://www.{BLOCKED}mworld.50webs.com"
To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home""
- From: Start Page = "http://www.{BLOCKED}mworld.50webs.com"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- From: Start Page = "http://www.{BLOCKED}mworld.50webs.com"
To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome""
- From: Start Page = "http://www.{BLOCKED}mworld.50webs.com"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Shell = "Explorer.exe system3_.exe"
To: Shell = ""Explorer.exe""
- From: Shell = "Explorer.exe system3_.exe"
Step 6
Search and delete these components
- d:\New Folder.exe
- d:\system3_.exe
- d:\autorun.inf
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_OTORUN.BF. 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.
Did this description help? Tell us how we did.