WORM_AUTORUN.SM
Microsoft: Worm:Win32/Autorun.N; Kaspersky: Worm.Win32.AutoRun.ble
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
It adds the Image File Execution Options registry entries to automatically execute itself whenever certain applications are run.
This worm arrives via removable drives. It may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This worm arrives via removable drives.
It may be downloaded by other malware/grayware/spyware from remote sites.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This worm drops the following files:
- %System%\Remember.dll - copy of urlmon.dll
- %System%\1.inf - autorun component
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It drops the following copies of itself into the affected system:
- %System%\snowfall.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It adds the following processes:
- spoolsv.exe
Propagation
This worm drops the following copy of itself in all physical and removable drives:
- snow.exe
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[autorun]
shell\open={garbage codes}
shell\open\Command=snow.exe
shell\open\Default=1
shell\explore={garbage codes}
shell\explore\command=snow.exe
Download Routine
This worm accesses the following websites to download files:
- http://{BLOCKED}m.{BLOCKED}2.org/zhanshi/Menu/hf.exe
- http://{BLOCKED}m.{BLOCKED}2.org/zhanshi/Menu/2007.exe
- http://{BLOCKED}m.{BLOCKED}2.org/zhanshi/Menu/dh.exe
It saves the files it downloads using the following names:
- C:\I.exe
- C:\Love.exe
- C:\Sbl.exe
As of this writing, the said sites are inaccessible.
NOTES:
It adds the following Image File Execution Options registry entries to automatically execute itself whenever certain applications are run:
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\
Image File Execution Options\{application name}
Debugger = %System%\snowfall.exe
{application name} may be any of the following:
- 360rpt.exe
- 360Safe.exe
- 360tray.exe
- adam.exe
- AgentSvr.exe
- AppSvc32.exe
- autoruns.exe
- avgrssvc.exe
- AvMonitor.exe
- avp.com
- avp.exe
- CCenter.exe
- ccSvcHst.exe
- FileDsty.exe
- FTCleanerShell.exe
- HijackThis.exe
- IceSword.exe
- iparmo.exe
- Iparmor.exe
- isPwdSvc.exe
- kabaload.exe
- KaScrScn.SCR
- KASMain.exe
- KASTask.exe
- KAV32.exe
- KAVDX.exe
- KAVPFW.exe
- KAVSetup.exe
- KAVStart.exe
- KISLnchr.exe
- KMailMon.exe
- KMFilter.exe
- KPFW32.exe
- KPFW32X.exe
- KPFWSvc.exe
- KRegEx.exe
- KRepair.COM
- KsLoader.exe
- KVCenter.kxp
- KvDetect.exe
- KvfwMcl.exe
- KVMonXP.kxp
- KVMonXP_1.kxp
- kvol.exe
- kvolself.exe
- KvReport.kxp
- KVSrvXP.exe
- KVStub.kxp
- kvupload.exe
- kvwsc.exe
- KvXP.kxp
- KWatch.exe
- KWatch9x.exe
- KWatchX.exe
- loaddll.exe
- MagicSet.exe
- mcconsol.exe
- mmqczj.exe
- mmsk.exe
- NAVSetup.exe
- nod32krn.exe
- nod32kui.exe
- PFW.exe
- PFWLiveUpdate.exe
- QHSET.exe
- Ras.exe
- Rav.exe
- RavMon.exe
- RavMonD.exe
- RavStub.exe
- RavTask.exe
- RegClean.exe
- rfwcfg.exe
- RfwMain.exe
- rfwProxy.exe
- rfwsrv.exe
- RsAgent.exe
- Rsaupd.exe
- runiep.exe
- safelive.exe
- scan32.exe
- shcfg32.exe
- SmartUp.exe
- SREng.exe
- symlcsvc.exe
- SysSafe.exe
- TrojanDetector.exe
- Trojanwall.exe
- TrojDie.kxp
- UIHost.exe
- UmxAgent.exe
- UmxAttachment.exe
- UmxCfg.exe
- UmxFwHlp.exe
- UmxPol.exe
- UpLive.EXE
- WoptiClean.exe
- zxsweep.exe
- sos.exe
- auto.exe
- UFO.exe
- AutoRun.exe
- XP.exe
- taskmgr.exe
- ShuiNiu.exe
- Systom.exe
- svch0st.exe
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
Identify and terminate files detected as WORM_AUTORUN.SM
- 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
Search and delete this file
Step 4
Search and delete AUTORUN.INF files created by WORM_AUTORUN.SM that contain these strings
shell\open={garbage codes}
shell\open\Command=snow.exe
shell\open\Default=1
shell\explore={garbage codes}
shell\explore\command=snow.exe
Step 5
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 NT\CURRENTVERSION\Image File Execution Options
- {application name}
- {application name}
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.SM. 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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