ENSRT Incident Note ETS-i-2005-12597
The Enterasys 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.Rontokbro.D@mm
Release Date: 10/14/2005
Last Updated:
Overview
Worm W32.Rontokbro.D@mm spreads via SMTP utilizing addresses gathered from the infected computer. The worm overwrites files and causes system instability.
Details below describe the characteristics of W32.Rontokbro.D@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.Rontokbro.D@mm arrives via an e-mail from a spoofed sender address and with a blank subject field. The message contained within the e-mail is the following:
BRONTOK.A [ By: H[REMOVED]M Community ]
-- Hentikan kebobrokan di negeri ini --
1. Adili Koruptor, Penyelundup, Tukang Suap, Penjudi, & Bandar NARKOBA
( Send to "NUSAKAMBANGAN")
2. Stop Free Sex, Absorsi, & Prostitusi
3. Stop (pencemaran laut & sungai), pembakaran hutan & perburuan liar.
4. SAY NO TO DRUGS !!!
-- KIAMAT SUDAH DEKAT --
Terinspirasi oleh: Elang Brontok (Spizaetus Cirrhatus) yang hampir punah[ By: H[REMOVED]unity --
If the attachment, "Kangen.exe", is executed, the following actions are taken against the conquered PC.
1. The worm copies itself into various directories within the infected system.
2. Overwrites the Autoexec.bat file of the infected system
3. Creates registry entries to ensure the worm is restarted on Windows system bootup.
4. Adds a task to the Windows scheduler so that "%Windir\Tasks\At1.job"
task is executed at 5:08 PM every day.
5. Restarts the infected PC when a window with specific titles is detected.
6. Spreads the worm via SMTP to e-mail addresses collected from the infected machine.
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.
Remediation
| Matrix N-Series | X |
| Matrix E7 | X |
| Matrix E6 | X |
| Matrix E5 | X |
| Matrix E1 | X |
| VH | X |
| C-Series | X | B-Series | X |
Detection
A specific Dragon signature has been created to detect the W32.Rontokbro.D@mm worm. This signature can be retrieved via Dragon Live Update and is located in the Master Library within the ENSRT category. The "ENSRT:W32-RONTOKBRO-D-001" signature can be copied into a custom library and deployed on Dragon sensors that are protecting the enterprise SMTP server to successfully detect end-user class machines which have become infected with the worm.
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 provided a quarantine policy. Once isolated, see your anti-virus vendor for Windows repair procedures for infected users.
References
http://securityresponse.symantec.com/avcenter/venc/data/w32.rontokbro.d@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: 10/14/2005 |
Author: ENSRT STAFF |
Change |