ENSRT Incident Note ETS-i-2005-12579
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 - WORM_BOBAX.P
Release Date: 06/06/2005
Last Updated:
Overview
The WORM_BOBAX.P mass-mailing worm spreads by utilizing its own embedded SMTP engine to forward copies of itself to all addresses retrieved from files located on the infected computer. The worm threatens network security by lowering security settings on the infected PC.
Also known as: W32.Bobax.Z@mm, W32/Bobax.worm
Details below will describe the characteristics of WORM_BOBAX.P 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
The WORM_BOBAX.P mass mailer arrives in the user's mailbox using a wide array of spoofed e-mail addresses and an e-mail subject line that will contain one of the following:
- bush
- Cool
- funny
- joke
- pics
- secret
The e-mail will include one of the following bodies:
- Attached some pics that i found
- Check this out :-)
- Hello,
- I was going through my album, and look what I found..
- Long time! Check this out!
- Osama Bin Laden Captured.
- Remember this?
- Saddam Hussein - Attempted Escape, Shot dead
- Secret!
- Testing
These potential e-mail bodies are followed by one of the following strings:
- +++ Attachment: No Virus found
- +++ F-Secure AntiVirus - You are protected
- +++ Norman AntiVirus - You are protected
- +++ Norton AntiVirus - You are protected
- +++ Panda AntiVirus - You are protected
- +++ www.f-secure.com
- +++ www.norman.com
- +++ www.pandasoftware.com
- +++ www.symantec.com
The e-mail will also contain one of the following attachments with either a .PIF, .EXE or .SCR extension:
- bush
- funny
- joke
- pics
- secret
The attachment is actually a copy of the trojan TROJ_SMALL.AHE which downloads the WORM_BOBAX.P worm from one of several Internet web sites. The worm will drop a copy of itself into the Windows system folder using a random file name and alter the system registry so that the worm is run at Windows system startup. Registry entries are also altered so that security settings are lowered on the infected PC
WORM_BOBAX.P then gathers e-mail addresses from the Windows Address Book, the .NET Messenger Service, and MS Outlook address book cached files and then sends multiple copies of itself to each contact on the list using an embedded SMTP engine.
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.
Trojans or backdoor listeners if not addressed through prudent remediation steps, can compromise network and host security. Additionally, trojans and backdoor listeners potentially allow theft of information, unauthorized remote access, and damage to critical files.
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 WORM_BOBAX.P worm can be retrieved via Dragon Live Update and are located in the Master Library within the ENSRT category. The nine signatures with the prefix "ENSRT: WORM-BOBAX-P" can be copied into a custom library and deployed on a Dragon network sensor that is protecting the enterprise SMTP server to successfully detect end-user class machines which have become infected with the worm.
Note: Due to the similarities in attack parameters, signatures created to detect the BOBAX.P worm may also detect the NETSKY.P worm.
If utilizing Dynamic Intrusion Response (DIR), a Dragon Alarmtool policy that consists of an event group that contains all of the signatures within the "ENSRT: WORM-BOBAX-P " family should be used. A threshold parameter of at least three signature detections within a time span of 60 seconds should be used to mitigate the existence of false positives.
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 quarantine VLAN or disabling the associated switch port for the user.
Using Enterasys Policy Manager, enforce a policy that allows SMTP traffic from end user PCs to authorized SMTP mail servers and blocks SMTP traffic to unauthorized end users or unknown Internet systems. If the SMTP protocol is not implemented for end users within the enterprise, consider implementing a policy blocking SMTP traffic from end user ports.
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://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=WORM%5FBOBAX%2EP&VSect=P
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A copy of the text of this section is an uncontrolled copy, and may lack important information or contain factual errors. All information herein is Copyright ©Enterasys Networks, Inc. All rights reserved. All information above is subject to change without notice.
Revision History:
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Version: 1.0 |
Date: 06/06/2005 |
Author: ENSRT STAFF |
Change |