Offered new rule for detect last Outlook/Crypto API...

[rmkml <rmkml () yahoo fr>]

Hi,

ok first, I have developped this rule during my new project: http://etplc.org

Thx Nruns company for recently released an old design bug in Microsoft Outlook/Crypto API X.509:

http://blog.nruns.com/blog/2013/11/12/A-portscan-by-email-Alex/
http://seclists.org/fulldisclosure/2013/Nov/84

Please found a "specific" rule release for detecting this:

alert tcp $EXTERNAL_NET any -> $SMTP_SERVERS $SMTP_PORTS (msg:"SMTP SPECIFIC Microsoft Outlook/Crypto API X.509 design 
bug allow blind HTTP requests attempt";
flow:to_server,established; content:"multipart/signed|3B|"; nocase; 
content:"application/pkcs7-signature|3B|"; nocase; distance:0; 
content:"|0A|QUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFB|0D|"; distance:0;
reference:cve,2013-3870; reference:url,www.microsoft.com/technet/security/bulletin/MS13-068.mspx; 
reference:url,blog.nruns.com/blog/2013/11/12/A-portscan-by-email-Alex; 
classtype:attempted-admin; sid:95420; rev:1;)

Maybe this rule or others will be improved in future (using file_data for decoding base64, checking x509 certificate 
1.1.1.1..., checking UA CryptoAPI outgoing proxy...).

Don't remember checking snort variables like $SMTP_SERVERS...

All comments are welcome.

Regards
@Rmkml

------------------------------------------------------------------------------
DreamFactory - Open Source REST & JSON Services for HTML5 & Native Apps
OAuth, Users, Roles, SQL, NoSQL, BLOB Storage and External API Access
Free app hosting. Or install the open source package on any LAMP server.
Sign up and see examples for AngularJS, jQuery, Sencha Touch and Native!
http://pubads.g.doubleclick.net/gampad/clk?id=63469471&iu=/4140/ostg.clktrk
_______________________________________________
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!