ENSRT Incident Note ETS-i-2005-12533
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_BAGLE.BE
Release Date: 03/01/2005
Last Updated:
Overview
The WORM_BAGLE.BE worm is an SMTP mass-mailing worm deeply integrated with the trojan TROJ_BAGLE.BE. The malware combination makes use of SMTP mass-mailing techniques, downloading additional components via HTTP, as well as installing a backdoor listener on TCP port 80.
Also known as: W32.Beagle.BG@mm
Details below will describe the characteristics of WORM_BAGLE.BE and TROJ_BAGLE.BE 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 TROJ_BAGLE.BE trojan arrives in the user's mailbox via an e-mail and embedded in the zip file attachment. The characteristics of the worm-ridden e-mail follow below. The subject of the email is blank while the message body contains one of the two following messages:
- price
- new price
The zip file attachment is named one of the following:
- 08_price.zip
- new__price.zip
- new_price.zip
- newprice.zip
- price_08.zip
- price_new.zip
- price2.zip
If executed, the trojan attempts to download the mass mailing component, WORM_BAGLE.BE, from one of dozens of potential WEB urls. The mass-mailing component is initially download as a "jpg" file with the name "zo2.jpg".
If the mass-mailing component is successfully downloaded, e-mail addresses are collected from the Windows Address Book for further proliferation. Mass-mailing proliferation is attempted by using the Internet based SMTP server "smtp.earthlink.net", the infected system's own Exchange server, or lastly the mail server at IP address 217.5.97.137.
In addition to mass-mailing components, the WORM_BAGLE.BE worm downloads an additional list of e-mail addresses for further propagation from the the "oceancareers.com" domain.
Lastly, the WORM_BAGLE.BE opens a backdoor component with a WEB server listeding on TCP port 80. The WEB server is configured with a pre-determined password to allow access to malicious remote users.
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
A specific set of Dragon signatures to detect the WORM_BAGLE.BE worm can be retrieved via Dragon Live Update and are located in the Master Library within the ENSRT category and prefixed with "ENSRT:WORM-BAGLE-BE". Copying these two signatures to a Dragon custom library and deploying on a network sensor protecting Internet connections will detect the WEB based downloading of the BAGLE.BE components.
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
Internet or edge facing firewalls should be configured with a default 'Deny' policy and contain 'Permit' policies for only needed services and applications. Furthermore, careful inspection of firewall policies that allow TCP traffic streams to be initiated from the Internet into internal enterprise resources is required. These policies should only allow specific protocols to trusted servers thereby combating the increased use of random TCP ports by Internet trojans and worms. In the case of the BAGLE.BE worm, careful attention should be paid to assure that firewall policies allow only HTTP traffic initiated from the Internet into enterprise WEB servers and not end-users.
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.
Apply the below available NetSight PMD file and apply the policy to user ports to block the WORM_BAGLE.BE worm's backdoor listener on TCP port 80.
This NetSight PMD file can be downloaded from here: http://www.enterasys.com/support/pmd.html?12533
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.
Scan all clients and servers for newly opened TCP ports that did not appear in previous TCP scans. If viruses are detected apply appropriate removal tools on each client and server that have the open ports (See your anti-virus solution for removal instructions).
References
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=WORM%5FBAGLE%2EBE&VSect=T
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=TROJ%5FBAGLE%2EBE&VSect=T
http://securityresponse.symantec.com/avcenter/venc/data/w32.beagle.bg@mm.html
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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: 03/01/2005 |
Author: ENSRT STAFF |
Change |