ENSRT Incident Note ETS-i-2005-12522
The Enterasys Networks Security Response Team (ENSRT) publishes incident notes to provide information for our constituents to raise awareness of issues deemed threatening to the security and integrity of our customers.
Worm - W32.Aimdes.A@mm
Release Date: 02/15/2005
Last Updated:
Overview
W32.Aimdes.A@mm is a Microsoft Windows mass-mailing worm containing an executable attachment that spreads via AOL Instant Messenger and MAPI protocol used by the Microsoft Exchange Server.
Details below will describe the characteristics of the W32.Aimdes.A@mm as well as provide detection, containment, and prevention techniques available through Enterasys Secure Networks solutions.
Systems affected
Windows operating systemsSystems not affected
Linux and MAC/OSXDescription
W32.Aimdes.A@mm mass mailer arrives in the user's mailbox as an e-mail with the following subject line:
- "Service Pack 2 BUG!!"
The e-mail also contains the following body:
- "Dear user I have been informed that there was a BUG in Windows Service Pack 2 which was fixed I recommend you to download this Patch version which will fix the bug and keep your system safe.
You will find the Patch file in the attachment, feal free to send it to anyone.
I'll be in touch with you as soon as another bug is found.
Regards,
A.H"
The W32.Aimdes.A@mm e-mail as described above contains an executable attachment called: "C:\Fix_SP2.zip"
The W32.Aimdes.A@mm worm is also spread via AOL Instant Messenger. The worm will send an Instant Message with the following text:
- "Hey whats up!! look what I did to my hair...lol!!"
The W32.Aimdes.A@mm will attempt to send a file transfer over AOL Instant Messenger called:
- "C:\Windows\picture.pif"
If the attached executable file is launched, the mass mailling worm will infect the PC and begin the replication process. First, the worm places new files with the name "msVBdll.exe" and "msVBdll.pif" into the Windows system directory and causes it to be launched at Windows boot time by updating certain system registry keys.
Secondly, the W32.Aimdes.A@mm worm attempts to disable numerous system and security processes as well as registry editing tools.
Third, the W32.Aimdes.A@mm worm creates a pop up dialogue box containing one of the following messages:
- "Title: "Blow Me"
Text: "Hello Windows has suffered from a serious error, it may never recover unless you perform oral sec on the cd drive""
- "Title: "Disgusting"
Text: "You are viewing this message because someone in the house is homosexual""
The fourth action that W32.Aimdes.A@mm attempts is to try to send the "C:\Fix_SP2.zip" file to other users on the host's buddy list through AOL Instant Messenger.
The fifth process involves an attempt to download the file "ahkerb.zip" from the website "http://geocities.com/vip_asshole/" and save this file as "C:\Fix_SP2.zip"
Sixth, W32.Aimdes.A@mm will use the MAPI protocol to send an e-mail containing the "C:\Fix_SP2.zip" file to all the addresses found in the Outlook Address book . After sending the e-mails, it deletes the sent e-mails and the "C:\Fix_SP2.zip" file.
Lastly, W32.Aimdes.A@mm terminates the "svchost.exe" and "lsass.exe" processes and puts the computer to sleep. It then attempts to copy itself to "A:\homework.exe"
Threat Assessment
Mass-mailing worms if not addressed through prudent remediation steps may congest mail servers and/or degrade network performance. Mass-mailing worms may impact individual system performance and compromise security settings allowing unauthorized remote access to the compromised host.
AOL Instant Messenger worms if not addressed through prudent remediation steps may impact individual system performance and compromise security settings by allowing unauthorized remote access to the compromised host.
Remediation
| Matrix N7 | X |
| Matrix E7 | X |
| Matrix E6 | X |
| Matrix E5 | X |
| Matrix E1 | X |
| VH | X |
| C-Series | X |
Detection
Specific Dragon signatures that detect the W32.Aimdes.A@mm worm can be retrieved via Dragon Live Update. These signatures are located in the Master Library within the ENSRT category.
The ENSRT:W32-AIMDES-A-AIM signature is utilized to detect the AOL Instant Messenger communication that is sent along with the attached file that propagates the worm. Deploy this signature on Dragon NIDS devices protecting end-user switch ports.
The ENSRT:W32-AIMDES-A-001 detects the worm as it propogates to external mail domains. The worm can be detected as it is sent between the Microsoft Exchange Server and the SMTP server when accessing external mail domains. Deploy this signature on Dragon NIDS devices protecting the pathways to SMTP servers.
If utilizing Dynamic Intrusion Response (DIR), a Dragon Alarmtool policy that consists of an event group containing the "ENSRT:W32-AIMDES-A-AIM" signature should be used. Note: The "ENSRT:W32-AIMDES-A-001" should not be used with DIR as it does not detect the Aimdes worm as it travels from a user port.
NOTE: All signatures in the ENSRT library are disabled by default. These signatures must be enabled after they are imported into a custom library if they are to be successfully deployed.
Prevention
Trusted End System solutions are capable of monitoring various end system activity. TES is able to take immediate action such as firewalling specific IPs, TCP/UDP ports, applications, or placing the user into a Quarantine policy or VLAN until end system threat is mitigated. Learn more at: http://www.enterasys.com/solutions/secure-networks/trusted_end_system/
Containment
The Enterasys Dynamic Intrusion Response (DIR) solution can be utilized to remove infected end-users from the enterprise network by detecting the infection with a Dragon NIDS signature (see "Detection" section of this report), locating the user's connection point using Automated Security Manager's location services module, and either placing the user in a quarentine VLAN or disabling the associated switch port for the user.
Repair
Monitor Dragon Realtime Console for alerts that end-user PCs have become infected with the virus. If utilizing the DIR solution, users can either be expunged from the network or placed in a quarantine VLAN. Once isolated, see your anti-virus vendor for Windows repair procedures for infected users.
References
http://securityresponse.symantec.com/avcenter/venc/data/w32.aimdes.a@mm.html
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=WORM%5FAIMDES%2EA&VSect=T
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Revision History:
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Version: 1.0 |
Date: 02/15/2005 |
Author: ENSRT STAFF |
Change |