PE_DOWN.D-O
Windows 2000, XP, Server 2003
Threat Type: File infector
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This file infector may be dropped by other malware. However, as of this writing, the said sites are inaccessible.
It deletes certain file types, disabling programs and applications from properly running.
It infects by appending its code to target host files.
It drops copies of itself in all removable drives. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It deletes itself after execution.
TECHNICAL DETAILS
Arrival Details
This file infector may be dropped by the following malware:
- PE_DOWN.D
However, as of this writing, the said sites are inaccessible.
Other System Modifications
This file infector deletes the following file types:
- %System%\appmgmts.dll
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\AppMgmt
File Infection
This file infector infects the following file types:
- EXE
It infects by appending its code to target host files.
Propagation
This file infector creates the following folder in all physical and removable drives:
- recycle.{645FF040-5081-101B-9F08-00AA002F954E}
It drops copies of itself in all removable drives.
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]
OPEN=recycle.{645FF040-5081-101B-9F08-00AA002F954E}\uninstall.exe
shell\open=´ò¿ª(&O)
shell\open\Command=recycle.{645FF040-5081-101B-9F08-00AA002F954E}\uninstall.exe Show
shell\open\Default=1//
shell\explore=×ÊÔ´¹ÜÀíÆ÷(&X)
shell\explore\Command=recycle.{645FF040-5081-101B-9F08-00AA002F954E}\uninstall.exe Show
Dropping Routine
This file infector drops the following files:
- %System%\dmutilio.dll - detected as TROJ_HORST.JY
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Other Details
Based on analysis of the codes, it has the following capabilities:
It also creates a registry entry for certain application names located under the following key:
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT
- CurrentVersion\Image File Execution Options
The created entry contains the following data value:
-
Debugger = "ntsd"
Affected application keys are as follows:
- 360SoftMgrSvc.exe
- 360hotfix.exe
- 360rp.exe
- 360rpt.exe
- 360safe.exe
- 360safebox.exe
- 360sd.exe
- 360se.exe
- 360speedld.exe
- 360tray.exe
- AvastUI.exe
- CCenter.exe
- FilMsg.exe
- KVMonXP.exe
- KVMonXP.kxp
- KVSrvXP.exe
- MPMon.exe
- MPSVC.exe
- MPSVC1.exe
- MPSVC2.exe
- McNASvc.exe
- McProxy.exe
- McSACore.exe
- Mcagent.exe
- Mcods.exe
- Mcshield.exe
- MpfSrv.exe
- RavMonD.exe
- RavTask.exe
- RsAgent.exe
- RsTray.exe
- ScanFrm.exe
- SfCtlCom.exe
- SpIDerMl.exe
- TMBMSRV.exe
- TmProxy.exe
- Twister.exe
- UfSeAgnt.exe
- afwServ.exe
- ast.exe
- avcenter.exe
- avfwsvc.exe
- avgnt.exe
- avguard.exe
- avmailc.exe
- avp.exe
- avshadow.exe
- avwebgrd.exe
- bdagent.exe
- ccSvcHst.exe
- dwengine.exe
- egui.exe
- ekrn.exe
- kavstart.exe
- kissvc.exe
- kmailmon.exe
- kpfw32.exe
- kpfwsvc.exe
- kpopserver.exe
- krnl360svc.exe
- ksmgui.exe
- ksmsvc.exe
- kswebshield.exe
- kwatch.exe
- kwstray.exe
- kxedefend.exe
- kxesapp.exe
- kxescore.exe
- kxeserv.exe
- kxetray.exe
- livesrv.exe
- mcmscsvc.exe
- mcsysmon.exe
- mcvsshld.exe
- msksrver.exe
- qutmserv.exe
- rsnetsvr.exe
- safeboxTray.exe
- sched.exe
- seccenter.exe
- spideragent.exe
- spidernt.exe
- spiderui.exe
- vsserv.exe
- zhudongfangyu.exe
It attempts to access the following websites to download files, which are possibly malicious:
- http://{BLOCKED}.{BLOCKED}.85.199/cl/80.exe
- http://{BLOCKED}.{BLOCKED}.113.108/msdownload/update/v5/redir/wuredirt.rar
- http://{BLOCKED}t.mvps.org/resources/tools/getpublicip.shtml
- http://{BLOCKED}{BLOCKED}.85.205/msdownload/update/v5/redir/wuredirt.rar
It deletes itself after execution.
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
Remove the malware/grayware file dropped/downloaded by PE_DOWN.D-O. (Note: Please skip this step if the threat(s) listed below have already been removed.)
Step 3
Restart in Safe Mode
Step 4
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
- Debugger = ntsd
- Debugger = ntsd
Step 5
Search and delete AUTORUN.INF files created by PE_DOWN.D-O that contain these strings
OPEN=recycle.{645FF040-5081-101B-9F08-00AA002F954E}\uninstall.exe
shell\open=´ò¿ª(&O)
shell\open\Command=recycle.{645FF040-5081-101B-9F08-00AA002F954E}\uninstall.exe Show
shell\open\Default=1//
shell\explore=×ÊÔ´¹ÜÀíÆ÷(&X)
shell\explore\Command=recycle.{645FF040-5081-101B-9F08-00AA002F954E}\uninstall.exe Show
Step 6
Scan your computer with your Trend Micro product to delete files detected as PE_DOWN.D-O. 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 this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
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