Snort mailing list archives
Re: UTF-8 BOM
From: Joel Esler <jesler () sourcefire com>
Date: Mon, 8 Apr 2013 16:10:37 -0400
How about something like this James? (Three rules) alert tcp $EXTERNAL_NET any -> $SMTP_SERVERS 25 (msg:"MALWARE-OTHER UTF-8 BOM in zip file attachment detected"; flow:to_server,established; content:".zip"; fast_pattern:only; content:"Content-Disposition: attachment|3B|"; content:"filename="; nocase; pcre:"/filename=[^\n]*?\x2ezip[\x22\x27\s]/si"; file_data; content:"|EF BB BF 50 B4|"; depth:5; metadata:policy balanced-ips drop, policy security-ips drop, ruleset community, service smtp; reference:url,http://blogs.mcafee.com/mcafee-labs/phishing-threat-uses-utf-8-bom-in-zip-signature-to-evade-detection; classtype:trojan-activity;) alert tcp $EXTERNAL_NET [110,143] -> $HOME_NET any (msg:"MALWARE-OTHER UTF-8 BOM in zip file attachment detected"; flow:to_client,established; content:".zip"; fast_pattern:only; content:"Content-Disposition: attachment|3B|"; content:"filename="; nocase; pcre:"/filename=[^\n]*?\x2ezip[\x22\x27\s]/si"; file_data; content:"|EF BB BF 50 B4|"; depth:5; metadata:policy balanced-ips drop, policy security-ips drop, ruleset community, service imap, service pop3; reference:url,http://blogs.mcafee.com/mcafee-labs/phishing-threat-uses-utf-8-bom-in-zip-signature-to-evade-detection; classtype:trojan-activity;) alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"MALWARE-OTHER UTF-8 BOM in zip file attachment detected"; flow:to_client,established; content:".zip"; fast_pattern:only; http_header; content:"filename="; nocase; http_header; pcre:"/filename=[^\n]*?\x2ezip[\x22\x27\s]/si"; file_data; content:"|EF BB BF 50 B4|"; depth:5; metadata:policy balanced-ips drop, policy security-ips drop, ruleset community, service http; reference:url,http://blogs.mcafee.com/mcafee-labs/phishing-threat-uses-utf-8-bom-in-zip-signature-to-evade-detection; classtype:trojan-activity;) On Apr 8, 2013, at 3:50 PM, James Lay <jlay () slave-tothe-box net> wrote:
It's a Monday, so let's start with something exciting: alert tcp $EXTERNAL_NET any -> $HOME_NET 25 (msg:"SPECIFIC-THREATS UTF-8 BOM in ZIP"; flow:to_server,established; file_data; content:"zip"; content:"|EF BB BF 50 B4|"; metadata:policy balanced-ips drop, policy security-ips drop, service smtp; reference:url,http://blogs.mcafee.com/mcafee-labs/phishing-threat-uses-utf-8-bom-in-zip-signature-to-evade-detection; classtype:trojan-activity; sid:10000045; rev:1;) Or not ;)..thoughts/cleanups/anything_that_would_make_this_useful are welcome. James ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ Snort-sigs mailing list Snort-sigs () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-sigs http://www.snort.org Please visit http://blog.snort.org for the latest news about Snort!
------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ Snort-sigs mailing list Snort-sigs () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-sigs http://www.snort.org Please visit http://blog.snort.org for the latest news about Snort!
Current thread:
- UTF-8 BOM James Lay (Apr 08)
- Re: UTF-8 BOM Joel Esler (Apr 08)
- Re: UTF-8 BOM James Lay (Apr 08)
- Re: UTF-8 BOM Joel Esler (Apr 08)
- Re: UTF-8 BOM rmkml (Apr 09)
- Re: UTF-8 BOM Joel Esler (Apr 09)
- Re: UTF-8 BOM James Lay (Apr 08)
- Re: UTF-8 BOM Joel Esler (Apr 08)