Discovered: April 2, 2004
Updated: February 13, 2007 12:20:39 PM
Type: Worm
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows XP
When W32.Gaobot.UM is executed, it performs the following actions:
- Copies and executes itself as %System%\Sysconf.exe.
Note: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
- Adds the value:
"Video Process"="sysconf.exe"
to the registry keys:
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
RunServices
so that the worm runs when you start Windows.
- Ends processes that are associated with antivirus and firewall software. Refer to "Processes" at the end of this section for a list of the process names.
- Attempts to end the following processes, which are associated with other worms:
- taskmon.exe
- bbeagle.exe
- d3dupdate.exe
- winsys.exe
- ssate.exe
- i11r54n4.exe
- rate.exe
- irun4.exe
- Ssate.exe
- Appends the following lines to the infected computer's hosts file:
127.0.0.1 www.trendmicro.com
127.0.0.1 trendmicro.com127.0.0.1 rads.mcafee.com
127.0.0.1 customer.symantec.com
127.0.0.1 liveupdate.symantec.com
127.0.0.1 us.mcafee.com
127.0.0.1 updates.symantec.com
127.0.0.1 update.symantec.com
127.0.0.1 www.nai.com
127.0.0.1 nai.com
127.0.0.1 secure.nai.com
127.0.0.1 dispatch.mcafee.com
127.0.0.1 download.mcafee.com
127.0.0.1 www.my-etrust.com
127.0.0.1 my-etrust.com
127.0.0.1 mast.mcafee.com
127.0.0.1 ca.com
127.0.0.1 www.ca.com
127.0.0.1 networkassociates.com
127.0.0.1 www.networkassociates.com
127.0.0.1 avp.com
127.0.0.1 www.kaspersky.com
127.0.0.1 www.avp.com
127.0.0.1 kaspersky.com
127.0.0.1 www.f-secure.com
127.0.0.1 f-secure.com
127.0.0.1 viruslist.com
127.0.0.1 www.viruslist.com
127.0.0.1 liveupdate.symantecliveupdate.com
127.0.0.1 mcafee.com
127.0.0.1 www.mcafee.com
127.0.0.1 sophos.com
127.0.0.1 www.sophos.com
127.0.0.1 symantec.com
127.0.0.1 securityresponse.symantec.com
127.0.0.1 www.symantec.com
- Connects to a predetermined IRC channel, using its own IRC client, and listens for commands. Some of the things that it can do are:
- Take a screenshot of the system
- Change the IRC server to which the worm connects
- Force a connection to a specified IRC channel
- Terminate the worm
- Have the worm send messages to people or channels on IRC
- Instruct the worm to send files from the system to the specified user over IRC (DCC Send)
- Download and execute files
- Steal system information
- Harvest email addresses
- Steal CD keys for various games
- Connect to FTP servers to upload files
- Terminate processes (other than those mentioned in step 4)
- Connect to other systems using SSH
- Run the worm as a SOCKS proxy server, making connections, which the attackers make, appear to come from the infected system.
- Attempts to spread to other computers by exploiting the following vulnerabilities:
- Probes the following shares:
- admin$
- c$
- d$
- e$
- print$
using various user names and weak passwords, as well as any user names found using NetUserEnum():
- Copies itself to any computers it compromised using the above exploits.
- If you go to www.paypal.com, it tries to steal PayPal login information by logging keystrokes. The worm can also be instructed to steal login information for several AOL services, including AOL Instant Messenger service (AIM).
Processes
W32.Gaobot.UL attempts to end the following processes:
- _AVP32.EXE
- _AVPCC.EXE
- _AVPM.EXE
- 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
- AVWIN95.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
- Claw95.EXE
- CLAW95CF.EXE
- CLEAN.EXE
- CLEANER.EXE
- CLEANER3.EXE
- CLEANPC.EXE
- CLICK.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
- ESCANH95.EXE
- ESCANHNT.EXE
- ESCANV95.EXE
- ESPWATCH.EXE
- ETHEREAL.EXE
- ETRUSTCIPE.EXE
- EVPN.EXE
- EXANTIVIRUS-CNET.EXE
- EXE.AVXW.EXE
- EXPERT.EXE
- EXPLORE.EXE
- F-AGNT95.EXE
- F-PROT.EXE
- F-PROT95.EXE
- F-STOPW.EXE
- FAMEH32.EXE
- FAST.EXE
- FCH32.EXE
- FIH32.EXE
- FINDVIRU.EXE
- FIREWALL.EXE
- FLOWPROTECTOR.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
- HIJACKTHIS.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
- ICLOAD95.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
- IPARMOR.EXE
- IRIS.EXE
- ISASS.EXE
- ISRV95.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
- NAVENGNAVEX15.NAVLU32.EXE
- NAVLU32.EXE
- NAVNT.EXE
- NAVSTUB.EXE
- NAVW32.EXE
- NAVWNT.EXE
- NC2000.EXE
- NCINST4.EXE
- NDD32.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
- PCC2002S902.EXE
- PCC2K_76_1436.EXE
- PCCIOMON.EXE
- PCCNTMON.EXE
- PCCWIN97.EXE
- PCCWIN98.EXE
- PCDSETUP.EXE
- PCFWALLICON.EXE
- PCIP10117_0.EXE
- PCSCAN.EXE
- PDSETUP.EXE
- PENIS.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
- PUSSY.EXE
- PVIEW95.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
- 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
- SCRSVR.EXE
- SCVHOST.EXE
- SD.EXE
- SERV95.EXE
- SERVICE.EXE
- SERVLCE.EXE
- SERVLCES.EXE
- SETUP_FLOWPROTECTOR_US.EXE
- SETUPVAMEEVAL.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
- SSG_4104.EXE
- SSGRATE.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
- TASKMO.EXE
- TASKMON.EXE
- TAUMON.EXE
- TBSCAN.EXE
- TC.EXE
- TCA.EXE
- TCM.EXE
- TDS-3.EXE
- TDS2-98.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
- WGFE95.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
Recommendations
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":
- Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
- Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
- Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
- Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
- Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
- Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
- If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
- Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
- Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
- Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
- Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
- If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
- For further information on the terms used in this document, please refer to the Security Response glossary.
Writeup By: Fergal Ladley