Bagi yang pakai Outlook Express.... ada berita menarik..... BTW mr spammer yang kemarin bikin "ulah" udah nggak nongol lagi ye, mungkin lagi coba daftar Carnegie Mellon U. :) -------------- CERT Advisory CA-99-06 ExploreZip Trojan Horse Program Original issue date: Thursday June 10, 1999 Source: CERT/CC Systems Affected Machines running Windows 95, Windows 98, or Windows NT. Any mail handling system could experience performance problems or a denial of service as a result of the propagation of this Trojan horse program. Overview The CERT Coordination Center continues to receive reports and inquiries regarding various forms of malicious executable files that are propagated as file attachments in electronic mail. Most recently, the CERT/CC has received reports of sites affected by ExploreZip, a Windows Trojan horse program. I. Description The CERT/CC has received reports of a Trojan horse program that is propagating in email attachments. This program is called ExploreZip. The number and variety of reports we have received indicate that this has the potential to be a widespread attack affecting a variety of sites. Our analysis indicates that this Trojan horse program requires the victim to run the attached zipped_files.exe program in order install a copy of itself and enable propagation. Based on reports we have received, systems running Windows 95, Windows 98, and Windows NT are the target platforms for this Trojan horse program. It is possible that under some mailer configurations, a user might automatically open a malicious file received in the form of an email attachment. This program is not known to exploit any new vulnerabilities. While the primary transport mechanism of this program is via email, any way of transferring files can also propagate the program. The ExploreZip Trojan horse has been propagated in the form of email messages containing the file zipped_files.exe as an attachment. The body of the email message usually appears to come from a known email correspondent, and may contain the following text: I received your email and I shall send you a reply ASAP. Till then, take a look at the attached zipped docs. The subject line of the message may not be predictable and may appear to be sent in reply to previous email. Opening the zipped_files.exe file causes the program to execute. At this time, there is conflicting information about the exact actions taken by zipped_files.exe when executed. One possible reason for conflicting information may be that there are multiple variations of the program being propagated, although we have not confirmed this one way or the other. Currently, we have the following general information on actions taken by the program. The program searches local and networked drives (drive letters C through Z) for specific file types and attempts to erase the contents of the files, leaving a zero byte file. The targets may include Microsoft Office files, such as .doc, .xls, and .ppt, and various source code files, such as .c, .cpp, .h, and .asm. The program propagates by replying to any new email that is received by an infected computer. A copy of zipped_files.exe is attached to the reply message. The program creates an entry in the Windows 95/98 WIN.INI file: run=C:\WINDOWS\SYSTEM\Explore.exe On Windows NT systems, an entry is made in the system registry: [HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows] run = "c:\winnt\system32\explore.exe" The program creates a file called explore.exe in the following locations: Windows 95/98 - c:\windows\system\explore.exe Windows NT - c:\winnt\system32\explore.exe This file is a copy of the zipped_files.exe Trojan horse, and the file size is 210432 bytes. MD5 (Explore.exe) = 0e10993050e5ed199e90f7372259e44b We will update this advisory with more specific information as we are able to confirm details. Please check the CERT/CC web site for the current version containing a complete revision history. II. Impact Users who execute the zipped_files.exe Trojan horse will infect the host system, potentially causing targeted files to be destroyed. Indirectly, this Trojan horse could cause a denial of service on mail servers. Several large sites have reported performance problems with their mail servers as a result of the propagation of this Trojan horse. III. Solution Use virus scanners In order to detect and clean current viruses you must keep your scanning tools up to date with the latest definition files. Please see the following anti-virus vendor resources for more information about the characteristics and removal techniques for the malicious file known as ExploreZip. Central Command http://www.avp.com/upgrade/upgrade.html Command Software Systems, Inc http://www.commandcom.com/html/virus/explorezip.html Computer Associates http://support.cai.com/Download/virussig.html Data Fellows http://www.datafellows.com/news/pr/eng/19990610.htm McAfee, Inc. (a Network Associates company) http://www.mcafee.com/viruses/explorezip/protecting_yourself.asp Network Associates Incorporated http://www.avertlabs.com/public/datafiles/valerts/vinfo/va10185.asp Sophos, Incorporated http://www.sophos.com/downloads/ide/index.html#explorez Symantec http://www.sarc.com/avcenter/download.html Trend Micro Incorporated http://www.antivirus.com/download/pattern.htm General protection from email Trojan horses and viruses Some previous examples of malicious files known to have propagated through electronic mail include False upgrade to Internet Explorer - discussed in CA-99-02 http://www.cert.org/advisories/CA-99-02-Trojan-Horses.html Melissa macro virus - discussed in CA-99-04 http://www.cert.org/advisories/CA-99-04-Melissa-Macro-Virus.html Happy99.exe Trojan Horse - discussed in IN-99-02 http://www.cert.org/incident_notes/IN-99-02.html CIH/Chernobyl virus - discussed in IN-99-03 http://www.cert.org/incident_notes/IN-99-03.html In each of the above cases, the effects of the malicious file are activated only when the file in question is executed. Social engineering is typically employed to trick a recipient into executing the malicious file. Some of the social engineering techniques we have seen used include Making false claims that a file attachment contains a software patch or update Implying or using entertaining content to entice a user into executing a malicious file Using email delivery techniques which cause the message to appear to have come from a familiar or trusted source Packaging malicious files in deceptively familiar ways (e.g., use of familiar but deceptive program icons or file names) The best advice with regard to malicious files is to avoid executing them in the first place. CERT advisory CA-99-02 discusses Trojan horses and offers suggestions to avoid them (please see Section V). http://www.cert.org/advisories/CA-99-02-Trojan-Horses.html Additional information Additional sources of virus information are listed at http://www.cert.org/other_sources/viruses.html - ---------------------------------------------------------------------------- ---- This document is available from: http://www.cert.org/advisories/CA-99-06-explorezip.html. - ---------------------------------------------------------------------------- ---- CERT/CC Contact Information Email: [EMAIL PROTECTED] Phone: +1 412-268-7090 (24-hour hotline) Fax: +1 412-268-6989 Postal address: CERT Coordination Center Software Engineering Institute Carnegie Mellon University Pittsburgh PA 15213-3890 U.S.A. CERT personnel answer the hotline 08:00-20:00 EST(GMT-5) / EDT(GMT-4) Monday through Friday; they are on call for emergencies during other hours, on U.S. holidays, and on weekends. Using encryption We strongly urge you to encrypt sensitive information sent by email. Our public PGP key is available from http://www.cert.org/CERT_PGP.key. If you prefer to use DES, please call the CERT hotline for more information. Getting security information CERT publications and other security information are available from our web site http://www.cert.org/. To be added to our mailing list for advisories and bulletins, send email to [EMAIL PROTECTED] and include SUBSCRIBE your-email-address in the subject of your message. Copyright 1999 Carnegie Mellon University. Conditions for use, disclaimers, and sponsorship information can be found in http://www.cert.org/legal_stuff.html. * "CERT" and "CERT Coordination Center" are registered in the U.S. Patent and Trademark Office - ---------------------------------------------------------------------------- ---- NO WARRANTY Any material furnished by Carnegie Mellon University and the Software Engineering Institute is furnished on an "as is" basis. Carnegie Mellon University makes no warranties of any kind, either expressed or implied as to any matter including, but not limited to, warranty of fitness for a particular purpose or merchantability, exclusivity or results obtained from use of the material. Carnegie Mellon University does not make any warranty of any kind with respect to freedom from patent, trademark, or copyright infringement. Revision History June 10, 1999: Initial release ------------------------------ http://www.securitysearch.net/cgi-bin/search/vote.cgi?ID=928555811 ------------------------------------------------------------------- untuk berhenti kirim email ke [EMAIL PROTECTED] untuk melihat peraturan kirim email ke [EMAIL PROTECTED] arsip berada di http://www.mail-archive.com/[email protected]
