************************************************************************** Security Bulletin 9430 DISA Defense Communications System December 7, 1994 Published by: DDN Security Coordination Center (SCC@NIC.DDN.MIL) 1-(800) 365-3642 DEFENSE DATA NETWORK SECURITY BULLETIN The DDN SECURITY BULLETIN is distributed by the DDN SCC (Security Coordination Center) under DISA contract as a means of communicating information on network and host security exposures, fixes, and concerns to security and management personnel at DDN facilities. Back issues may be obtained via FTP (or Kermit) from NIC.DDN.MIL [192.112.36.5] using login="anonymous" and password="guest". The bulletin pathname is scc/ddn-security-yynn (where "yy" is the year the bulletin is issued and "nn" is a bulletin number, e.g. scc/ddn-security-9428). ************************************************************************** + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + ! ! ! The following important advisory was issued by the Automated ! ! Systems Security Incident Support Team (ASSIST) and is being ! ! relayed unedited via the Defense Information Systems Agency's ! ! Security Coordination Center distribution system as a means ! ! of providing DDN subscribers with useful security information. ! ! ! + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bulletin 94-36 Release date: 6 December 1994, 7:00 AM EST SUBJECT: DOS Monkey Virus. SUMMARY: The virus strains known as 'Monkey' Virus also known as Monkey-1, Monkey-2, and Monkey-B' viruses infect the Master Boot Record (MBR) on hard disks and DOS boot record on diskettes. The Monkey virus family is a distant member of the Stoned virus family and is also a stealth type virus. The Monkey virus is spread only through diskettes. ASSIST has received multiple reports of these viruses infecting DoD systems. BACKGROUND: The Monkey Virus was first discovered in Edmonton, Canada, in 1991. The Monkey virus infects the Master Boot Record of hard disk and the DOS boot record on diskettes. The virus does not let the original partition table remain in its assigned place, instead it is relocated to the third sector and encrypted, and replaces it with its own code. If the system is booted from a diskette the hard drive is inaccessible and a DOS error message of 'Invalid drive specification' is generated. If the system is booted from the hard disk the virus is first executed then the system may be accessed normally. Thus the virus is difficult to detect. The virus is also a memory resident infector. Once the virus becomes memory resident all non-write protected diskettes will be infected if accessed by the system. Cleanup procedures improperly administered could result in a corrupted hard disk drive. The Monkey virus easily infects both the hard disk and diskette drives of a system. Once infected the system requires total removal of the virus to correct the condition. The removal of the virus may render the MBR as unrecoverable. The virus moves the return from interrupt 12 to 9FC0. IMPACT: Possible total/partial loss of data on the hard drive. RECOMMENDED SOLUTION: The IBM Anti-virus software will detect and clean the Monkey viruses. McAfee Antivirus has a program available (killmnk3.zip) that will remove the virus from infected systems. The U.S. Army has a site license for the McAfee Antivirus software. Most other major antivirus software packages will also detect the Monkey viruses, check with your vendor if you have a question about a specific product. Additional removal procedures are as follows: There are five different removal techniques discussed herein. The utilization of a commercially available antivirus product is recommended. The DoD has available such products for utilization. 1. Restore the original MBR and partition table from a backup taken prior to the infection. In DOS-5 this backup can be performed by using MIRROW /PARTN command. 2. Repartition the hard disk. After which the logical disk must be reformated. Note: all data is lost in this process. 3. Manually restore the MBR and partition tables using FDISK/MBR. The partition values must be calculated and inserted. Success is doubtful and requires expert knowledge of the disk structure. 4. Exploit the virus stealth capabilities by taking a copy of the zero track while the virus is active. This copy will contain the origianl MBR. This method is not recommended due to the risk of the diskettes being utilized in the copy process becoming infected. 5. Utilize a known commercial antivirus removal product. This is the process most successful and the one recommended. Note: The IBM Anti-virus product is site licensed to the DoD and is available from the ASSIST via FTP and through the ASSIST Bulletin Board System. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ASSIST is an element of the Defense Information Systems Agency (DISA), Center for Information Systems Security (CISS), that provides service to the entire DoD community. Constituents of the DoD with questions about ASSIST or computer security security issues, can contact ASSIST using one of the methods listed below. Non-DoD organizations/institutions, contact the Forum of Incident Response and Security Teams (FIRST) representative. To obtain a list of FIRST member organizations and their constituencies send an email to docserver@first.org with an empty "subject" line and a message body containing the line "send first-contacts". ASSIST Information Resources: To be included in the distribution list for the ASSIST bulletins, send your Milnet (Internet) e-mail address to assist-request@assist.mil. Back issues of ASSIST bulletins, and other security related information, are available from the ASSIST BBS at 703-756-7993/1154 DSN 289-7993/1154, and through anonymous FTP from assist.mil (IP address 199.211.123.11). Note: assist.mil will only accept anonymous FTP connections from Milnet addresses that are registered with the NIC or DNS. ASSIST Contact Information: PHONE: 800-357-4231 (or 703-756-7974 DSN 289), duty hours are 06:00 to 22:30 EST (GMT -5) Monday through Friday. During off duty hours, weekends and holidays, ASSIST can be reached via pager at 800-791- 4857. The page will be answered within 30 minutes, however if a quicker response is required, prefix the phone number with "999". ELECTRONIC MAIL: Send to assist@assist.mil. ASSIST BBS: Leave a message for the "sysop". Reference herein to any specific commercial product, process, or service by trade name, trademark manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by ASSIST. The views and opinions of authors expressed herein shall not be used for advertising or product endorsement purposes. **************************************************************************** * * * The point of contact for MILNET security-related incidents is the * * Security Coordination Center (SCC). * * * * E-mail address: SCC@NIC.DDN.MIL * * * * Telephone: 1-(800)-365-3642 * * * * NIC Help Desk personnel are available from 7:00 a.m.-7:00 p.m. EST, * * Monday through Friday except on federal holidays. * * * **************************************************************************** PLEASE NOTE: Some users outside of the DOD computing communities may receive DDN Security bulletins. If you are not part of the DOD community, please contact your agency's incident response team to report incidents. Your agency's team will coordinate with DOD. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained by sending email to docserver@first.org with an empty subject line and a message body containing the line: send first-contacts. This document was prepared as an service to the DOD community. Neither the United States Government nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government. The opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government, and shall not be used for advertising or product endorsement purposes.