BKDR_GAOBOT.SS
Worm:Win32/Gaobot (Microsoft); PAK:PE-Crypt.Wonk, Backdoor.Win32.Mytobor.b (Kaspersky); W32.Gaobot.gen!poly (Symantec); W32/Gaobot.worm.gen.d (McAfee); Backdoor.Gaobot (Sunbelt); W32/AgoBot.fam!worm (Fortinet); Backdoor.Win32.Agobot (Ikarus);
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk.
It modifies the affected system's HOSTS files. This prevents users from accessing certain websites.
TECHNICAL DETAILS
Arrival Details
This backdoor 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 backdoor drops the following copies of itself into the affected system:
- %System%\msnmsngr.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.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
WINDOWS SYSTEM = "msnmsngr.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WINDOWS SYSTEM = "msnmsngr.exe"
Backdoor Routine
This backdoor connects to any of the following IRC server(s):
- bilal2.{BLOCKED}s.net
It joins any of the following IRC channel(s):
- #hell
It executes the following command(s) from a remote malicious user:
- Download files
- Update copy of itself
- Execute files
- Port scanning
Process Termination
This backdoor terminates the following processes if found running in the affected system's memory:
- ACKWIN32.EXE
- ADAWARE.EXE
- ADVXDWIN.EXE
- AGENTSVR.EXE
- AGENTW.EXE
- ALERTSVC.EXE
- ALEVIR.EXE
- ALOGSERV.EXE
- AMON9X.EXE
- ANTI-TROJAN.EXE
- ANTIVIRUS.EXE
- ANTS.EXE
- APIMONITOR.EXE
- APLICA32.EXE
- APVXDWIN.EXE
- ARR.EXE
- ATCON.EXE
- ATGUARD.EXE
- ATRO55EN.EXE
- ATUPDATER.EXE
- ATWATCH.EXE
- AU.EXE
- AUPDATE.EXE
- AUTO-PROTECT.NAV80TRY.EXE
- AUTODOWN.EXE
- AUTOTRACE.EXE
- AUTOUPDATE.EXE
- AVCONSOL.EXE
- AVE32.EXE
- AVGCC32.EXE
- AVGCTRL.EXE
- AVGNT.EXE
- AVGSERV.EXE
- AVGSERV9.EXE
- AVGUARD.EXE
- AVGW.EXE
- AVKPOP.EXE
- AVKSERV.EXE
- AVKSERVICE.EXE
- AVKWCTl9.EXE
- AVLTMAIN.EXE
- AVNT.EXE
- AVP.EXE
- AVP32.EXE
- AVPCC.EXE
- AVPDOS32.EXE
- AVPM.EXE
- AVPTC32.EXE
- AVPUPD.EXE
- AVSCHED32.EXE
- AVSYNMGR.EXE
- AVWINNT.EXE
- AVWUPD.EXE
- AVWUPD32.EXE
- AVWUPSRV.EXE
- AVXMONITOR9X.EXE
- AVXMONITORNT.EXE
- AVXQUAR.EXE
- BACKWEB.EXE
- BARGAINS.EXE
- BD_PROFESSIONAL.EXE
- BEAGLE.EXE
- BELT.EXE
- BIDEF.EXE
- BIDSERVER.EXE
- BIPCP.EXE
- BIPCPEVALSETUP.EXE
- BISP.EXE
- BLACKD.EXE
- BLACKICE.EXE
- BLSS.EXE
- BOOTCONF.EXE
- BOOTWARN.EXE
- BORG2.EXE
- BPC.EXE
- BRASIL.EXE
- BS120.EXE
- BUNDLE.EXE
- BVT.EXE
- CCAPP.EXE
- CCEVTMGR.EXE
- CCPXYSVC.EXE
- CDP.EXE
- CFD.EXE
- CFGWIZ.EXE
- CFIADMIN.EXE
- CFIAUDIT.EXE
- CFINET.EXE
- CFINET32.EXE
- CLAW95CF.EXE
- CLEAN.EXE
- CLEANER.EXE
- CLEANER3.EXE
- CLEANPC.EXE
- CLICK.EXE
- CMD.EXE
- CMD32.EXE
- CMESYS.EXE
- CMGRDIAN.EXE
- CMON016.EXE
- CONNECTIONMONITOR.EXE
- CPD.EXE
- CPF9X206.EXE
- CPFNT206.EXE
- CTRL.EXE
- CV.EXE
- CWNB181.EXE
- CWNTDWMO.EXE
- DATEMANAGER.EXE
- DCOMX.EXE
- DEFALERT.EXE
- DEFSCANGUI.EXE
- DEFWATCH.EXE
- DEPUTY.EXE
- DIVX.EXE
- DLLCACHE.EXE
- DLLREG.EXE
- DOORS.EXE
- DPF.EXE
- DPFSETUP.EXE
- DPPS2.EXE
- DRWATSON.EXE
- DRWEB32.EXE
- DRWEBUPW.EXE
- DSSAGENT.EXE
- DVP95.EXE
- DVP95_0.EXE
- ECENGINE.EXE
- EFPEADM.EXE
- EMSW.EXE
- ENT.EXE
- ESAFE.EXE
- ESCANHNT.EXE
- ESCANV95.EXE
- ESPWATCH.EXE
- ETHEREAL.EXE
- ETRUSTCIPE.EXE
- EVPN.EXE
- EXANTIVIRUS-CNET.EXE
- EXE.AVXW.EXE
- EXPERT.EXE
- EXPLORE.EXE
- F-PROT.EXE
- F-PROT95.EXE
- F-STOPW.EXE
- FAMEH32.EXE
- FAST.EXE
- FCH32.EXE
- FIH32.EXE
- FINDVIRU.EXE
- FIREWALL.EXE
- FNRB32.EXE
- FP-WIN.EXE
- FP-WIN_TRIAL.EXE
- FPROT.EXE
- FRW.EXE
- FSAA.EXE
- FSAV.EXE
- FSAV32.EXE
- FSAV530STBYB.EXE
- FSAV530WTBYB.EXE
- FSAV95.EXE
- FSGK32.EXE
- FSM32.EXE
- FSMA32.EXE
- FSMB32.EXE
- GATOR.EXE
- GBMENU.EXE
- GBPOLL.EXE
- GENERICS.EXE
- GMT.EXE
- GUARD.EXE
- GUARDDOG.EXE
- HACKTRACERSETUP.EXE
- HBINST.EXE
- HBSRV.EXE
- HOTACTIO.EXE
- HOTPATCH.EXE
- HTLOG.EXE
- HTPATCH.EXE
- HWPE.EXE
- HXDL.EXE
- HXIUL.EXE
- IAMAPP.EXE
- IAMSERV.EXE
- IAMSTATS.EXE
- IBMASN.EXE
- IBMAVSP.EXE
- ICLOADNT.EXE
- ICMON.EXE
- ICSUPP95.EXE
- ICSUPPNT.EXE
- IDLE.EXE
- IEDLL.EXE
- IEDRIVER.EXE
- IEXPLORER.EXE
- IFACE.EXE
- IFW2000.EXE
- INETLNFO.EXE
- INFUS.EXE
- INFWIN.EXE
- INIT.EXE
- INTDEL.EXE
- INTREN.EXE
- IOMON98.EXE
- ISTSVC.EXE
- JAMMER.EXE
- JDBGMRG.EXE
- JEDI.EXE
- KAVLITE40ENG.EXE
- KAVPERS40ENG.EXE
- KAVPF.EXE
- KAZZA.EXE
- KEENVALUE.EXE
- KERIO-PF-213-EN-WIN.EXE
- KERIO-WRL-421-EN-WIN.EXE
- KERIO-WRP-421-EN-WIN.EXE
- KERNEL32.EXE
- KILLPROCESSSETUP161.EXE
- LAUNCHER.EXE
- LDNETMON.EXE
- LDPRO.EXE
- LDPROMENU.EXE
- LDSCAN.EXE
- LNETINFO.EXE
- LOADER.EXE
- LOCALNET.EXE
- LOCKDOWN.EXE
- LOCKDOWN2000.EXE
- LOOKOUT.EXE
- LORDPE.EXE
- LSETUP.EXE
- LUALL.EXE
- LUAU.EXE
- LUCOMSERVER.EXE
- LUINIT.EXE
- LUSPT.EXE
- MAPISVC32.EXE
- MCAGENT.EXE
- MCMNHDLR.EXE
- MCSHIELD.EXE
- MCTOOL.EXE
- MCUPDATE.EXE
- MCVSRTE.EXE
- MCVSSHLD.EXE
- MD.EXE
- MFIN32.EXE
- MFW2EN.EXE
- MFWENG3.02D30.EXE
- MGAVRTCL.EXE
- MGAVRTE.EXE
- MGHTML.EXE
- MGUI.EXE
- MINILOG.EXE
- MMOD.EXE
- MONITOR.EXE
- MOOLIVE.EXE
- MOSTAT.EXE
- MPFAGENT.EXE
- MPFSERVICE.EXE
- MPFTRAY.EXE
- MRFLUX.EXE
- MSAPP.EXE
- MSBB.EXE
- MSBLAST.EXE
- MSCACHE.EXE
- MSCCN32.EXE
- MSCMAN.EXE
- MSCONFIG.EXE
- MSDM.EXE
- MSDOS.EXE
- MSIEXEC16.EXE
- MSINFO32.EXE
- MSLAUGH.EXE
- MSMGT.EXE
- MSMSGRI32.EXE
- MSSMMC32.EXE
- MSSYS.EXE
- MSVXD.EXE
- MU0311AD.EXE
- MWATCH.EXE
- N32SCANW.EXE
- NAV.EXE
- NAVAP.NAVAPSVC.EXE
- NAVAPSVC.EXE
- NAVAPW32.EXE
- NAVDX.EXE
- NAVLU32.EXE
- NAVNT.EXE
- NAVSTUB.EXE
- NAVW32.EXE
- NAVWNT.EXE
- NC2000.EXE
- NCINST4.EXE
- NDD32.EXE
- NEC.EXE
- NEOMONITOR.EXE
- NEOWATCHLOG.EXE
- NETARMOR.EXE
- NETD32.EXE
- NETINFO.EXE
- NETMON.EXE
- NETSCANPRO.EXE
- NETSPYHUNTER-1.2.EXE
- NETSTAT.EXE
- NETUTILS.EXE
- NISSERV.EXE
- NISUM.EXE
- NMAIN.EXE
- NOD32.EXE
- NORMIST.EXE
- NORTON_INTERNET_SECU_3.0_407.EXE
- NOTSTART.EXE
- NPF40_TW_98_NT_ME_2K.EXE
- NPFMESSENGER.EXE
- NPROTECT.EXE
- NPSCHECK.EXE
- NPSSVC.EXE
- NSCHED32.EXE
- NSSYS32.EXE
- NSTASK32.EXE
- NSUPDATE.EXE
- NT.EXE
- NTRTSCAN.EXE
- NTVDM.EXE
- NTXconfig.EXE
- NUI.EXE
- NUPGRADE.EXE
- NVARCH16.EXE
- NVC95.EXE
- NVSVC32.EXE
- NWINST4.EXE
- NWSERVICE.EXE
- NWTOOL16.EXE
- OLLYDBG.EXE
- ONSRVR.EXE
- OPTIMIZE.EXE
- OSTRONET.EXE
- OTFIX.EXE
- OUTPOST.EXE
- OUTPOSTINSTALL.EXE
- OUTPOSTPROINSTALL.EXE
- PADMIN.EXE
- PANIXK.EXE
- PATCH.EXE
- PAVCL.EXE
- PAVPROXY.EXE
- PAVSCHED.EXE
- PAVW.EXE
- PCFWALLICON.EXE
- PCIP10117_0.EXE
- PCSCAN.EXE
- PDSETUP.EXE
- PERISCOPE.EXE
- PERSFW.EXE
- PERSWF.EXE
- PF2.EXE
- PFWADMIN.EXE
- PGMONITR.EXE
- PINGSCAN.EXE
- PLATIN.EXE
- POP3TRAP.EXE
- POPROXY.EXE
- POPSCAN.EXE
- PORTDETECTIVE.EXE
- PORTMONITOR.EXE
- POWERSCAN.EXE
- PPINUPDT.EXE
- PPTBC.EXE
- PPVSTOP.EXE
- PRIZESURFER.EXE
- PRMT.EXE
- PRMVR.EXE
- PROCDUMP.EXE
- PROCESSMONITOR.EXE
- PROCEXPLORERV1.0.EXE
- PROGRAMAUDITOR.EXE
- PROPORT.EXE
- PROTECTX.EXE
- PSPF.EXE
- PURGE.EXE
- QCONSOLE.EXE
- QSERVER.EXE
- RAPAPP.EXE
- RAV7.EXE
- RAV7WIN.EXE
- RAV8WIN32ENG.EXE
- RAY.EXE
- RB32.EXE
- RCSYNC.EXE
- REALMON.EXE
- REGED.EXE
- REGEDIT.EXE
- REGEDT32.EXE
- RESCUE.EXE
- RESCUE32.EXE
- RRGUARD.EXE
- RSHELL.EXE
- RTVSCAN.EXE
- RTVSCN95.EXE
- RULAUNCH.EXE
- RUN32DLL.EXE
- RUNDLL.EXE
- RUNDLL16.EXE
- RUXDLL32.EXE
- SAFEWEB.EXE
- SAHAGENT.EXE
- SAVE.EXE
- SAVENOW.EXE
- SBSERV.EXE
- SC.EXE
- SCAM32.EXE
- SCAN32.EXE
- SCAN95.EXE
- SCANPM.EXE
- SCRSCAN.EXE
- SETUPVAMEEVAL.EXE
- SETUP_FLOWPROTECTOR_US.EXE
- SFC.EXE
- SGSSFW32.EXE
- SH.EXE
- SHELLSPYINSTALL.EXE
- SHN.EXE
- SHOWBEHIND.EXE
- SMC.EXE
- SMS.EXE
- SMSS32.EXE
- SOAP.EXE
- SOFI.EXE
- SPERM.EXE
- SPF.EXE
- SPHINX.EXE
- SPOLER.EXE
- SPOOLCV.EXE
- SPOOLSV32.EXE
- SPYXX.EXE
- SREXE.EXE
- SRNG.EXE
- SS3EDIT.EXE
- SSGRATE.EXE
- SSG_4104.EXE
- ST2.EXE
- START.EXE
- STCLOADER.EXE
- SUPFTRL.EXE
- SUPPORT.EXE
- SUPPORTER5.EXE
- SVC.EXE
- SVCHOSTC.EXE
- SVCHOSTS.EXE
- SVSHOST.EXE
- SWEEP95.EXE
- SWEEPNET.SWEEPSRV.SYS.SWNETSUP.EXE
- SYMPROXYSVC.EXE
- SYMTRAY.EXE
- SYSEDIT.EXE
- SYSTEM.EXE
- SYSTEM32.EXE
- SYSUPD.EXE
- TASKMG.EXE
- TASKMGR.EXE
- TASKMO.EXE
- TASKMON.EXE
- TAUMON.EXE
- TBSCAN.EXE
- TC.EXE
- TCA.EXE
- TCM.EXE
- TDS-3.EXE
- TDS2-NT.EXE
- TEEKIDS.EXE
- TFAK.EXE
- TFAK5.EXE
- TGBOB.EXE
- TITANIN.EXE
- TITANINXP.EXE
- TRACERT.EXE
- TRICKLER.EXE
- TRJSCAN.EXE
- TRJSETUP.EXE
- TROJANTRAP3.EXE
- TSADBOT.EXE
- TVMD.EXE
- TVTMD.EXE
- UNDOBOOT.EXE
- UPDAT.EXE
- UPDATE.EXE
- UPGRAD.EXE
- UTPOST.EXE
- VBCMSERV.EXE
- VBCONS.EXE
- VBUST.EXE
- VBWIN9X.EXE
- VBWINNTW.EXE
- VCSETUP.EXE
- VET32.EXE
- VET95.EXE
- VETTRAY.EXE
- VFSETUP.EXE
- VIR-HELP.EXE
- VIRUSMDPERSONALFIREWALL.EXE
- VNLAN300.EXE
- VNPC3000.EXE
- VPC32.EXE
- VPC42.EXE
- VPFW30S.EXE
- VPTRAY.EXE
- VSCAN40.EXE
- VSCENU6.02D30.EXE
- VSCHED.EXE
- VSECOMR.EXE
- VSHWIN32.EXE
- VSISETUP.EXE
- VSMAIN.EXE
- VSMON.EXE
- VSSTAT.EXE
- VSWIN9XE.EXE
- VSWINNTSE.EXE
- VSWINPERSE.EXE
- W32DSM89.EXE
- W9X.EXE
- WATCHDOG.EXE
- WEBDAV.EXE
- WEBSCANX.EXE
- WEBTRAP.EXE
- WFINDV32.EXE
- WHOSWATCHINGME.EXE
- WIMMUN32.EXE
- WIN-BUGSFIX.EXE
- WIN32.EXE
- WIN32US.EXE
- WINACTIVE.EXE
- WINDOW.EXE
- WINDOWS.EXE
- WININETD.EXE
- WININIT.EXE
- WININITX.EXE
- WINLOGIN.EXE
- WINMAIN.EXE
- WINNET.EXE
- WINPPR32.EXE
- WINRECON.EXE
- WINSERVN.EXE
- WINSSK32.EXE
- WINSTART.EXE
- WINSTART001.EXE
- WINTSK32.EXE
- WINUPDATE.EXE
- WKUFIND.EXE
- WNAD.EXE
- WNT.EXE
- WRADMIN.EXE
- WRCTRL.EXE
- WSBGATE.EXE
- WUPDATER.EXE
- WUPDT.EXE
- WYVERNWORKSFIREWALL.EXE
- XPF202EN.EXE
- ZAPRO.EXE
- ZAPSETUP3001.EXE
- ZATUTOR.EXE
- ZONALM2601.EXE
- ZONEALARM.EXE
- _AVP32.EXE
- _AVPCC.EXE
- _AVPM.EXE
HOSTS File Modification
This backdoor modifies the affected system's HOSTS files to prevent a user from accessing the following websites:
- www.symantec.com
- securityresponse.symantec.com
- symantec.com
- www.sophos.com
- sophos.com
- www.mcafee.com
- mcafee.com
- liveupdate.symantecliveupdate.com
- www.viruslist.com
- viruslist.com
- viruslist.com
- f-secure.com
- www.f-secure.com
- kaspersky.com
- kaspersky-labs.com
- www.avp.com
- www.kaspersky.com
- avp.com
- www.networkassociates.com
- networkassociates.com
- www.ca.com
- ca.com
- mast.mcafee.com
- my-etrust.com
- www.my-etrust.com
- download.mcafee.com
- dispatch.mcafee.com
- secure.nai.com
- nai.com
- www.nai.com
- update.symantec.com
- updates.symantec.com
- us.mcafee.com
- liveupdate.symantec.com
- customer.symantec.com
- rads.mcafee.com
- trendmicro.com
- pandasoftware.com
- www.pandasoftware.com
- www.trendmicro.com
- www.grisoft.com
- www.microsoft.com
- microsoft.com
- www.virustotal.com
- virustotal.com
- www.amazon.com
- www.amazon.co.uk
- www.amazon.ca
- www.amazon.fr
- www.paypal.com
- paypal.com
- moneybookers.com
- www.moneybookers.com
- www.ebay.com
- ebay.com
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 BKDR_GAOBOT.SS
- 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
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\RunServices
- WINDOWS SYSTEM = "msnmsngr.exe"
- WINDOWS SYSTEM = "msnmsngr.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- WINDOWS SYSTEM = "msnmsngr.exe"
- WINDOWS SYSTEM = "msnmsngr.exe"
Step 4
Remove these strings added by the malware/grayware/spyware in the HOSTS file
- 127.0.0.1 www.symantec.com
- 127.0.0.1 securityresponse.symantec.com
- 127.0.0.1 symantec.com
- 127.0.0.1 www.sophos.com
- 127.0.0.1 sophos.com
- 127.0.0.1 www.mcafee.com
- 127.0.0.1 mcafee.com
- 127.0.0.1 liveupdate.symantecliveupdate.com
- 127.0.0.1 www.viruslist.com
- 127.0.0.1 viruslist.com
- 127.0.0.1 viruslist.com
- 127.0.0.1 f-secure.com
- 127.0.0.1 www.f-secure.com
- 127.0.0.1 kaspersky.com
- 127.0.0.1 kaspersky-labs.com
- 127.0.0.1 www.avp.com
- 127.0.0.1 www.kaspersky.com
- 127.0.0.1 avp.com
- 127.0.0.1 www.networkassociates.com
- 127.0.0.1 networkassociates.com
- 127.0.0.1 www.ca.com
- 127.0.0.1 ca.com
- 127.0.0.1 mast.mcafee.com
- 127.0.0.1 my-etrust.com
- 127.0.0.1 www.my-etrust.com
- 127.0.0.1 download.mcafee.com
- 127.0.0.1 dispatch.mcafee.com
- 127.0.0.1 secure.nai.com
- 127.0.0.1 nai.com
- 127.0.0.1 www.nai.com
- 127.0.0.1 update.symantec.com
- 127.0.0.1 updates.symantec.com
- 127.0.0.1 us.mcafee.com
- 127.0.0.1 liveupdate.symantec.com
- 127.0.0.1 customer.symantec.com
- 127.0.0.1 rads.mcafee.com
- 127.0.0.1 trendmicro.com
- 127.0.0.1 pandasoftware.com
- 127.0.0.1 www.pandasoftware.com
- 127.0.0.1 www.trendmicro.com
- 127.0.0.1 www.grisoft.com
- 127.0.0.1 www.microsoft.com
- 127.0.0.1 microsoft.com
- 127.0.0.1 www.virustotal.com
- 127.0.0.1 virustotal.com
- 127.0.0.1 www.amazon.com
- 127.0.0.1 www.amazon.co.uk
- 127.0.0.1 www.amazon.ca
- 127.0.0.1 www.amazon.fr
- 127.0.0.1 www.paypal.com
- 127.0.0.1 paypal.com
- 127.0.0.1 moneybookers.com
- 127.0.0.1 www.moneybookers.com
- 127.0.0.1 www.ebay.com
- 127.0.0.1 ebay.com
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_GAOBOT.SS. 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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