# (C) Copyright 2001-2004, Martin Roesch, Brian Caswell, et al.
#    All rights reserved.
# $Id$
#------------
# VIRUS RULES
#------------
#
# We don't care about virus rules anymore.  BUT, you people won't stop asking
# us for virus rules.  So... here ya go.
#
# There is now one rule that looks for any of the following attachment types:
#
#   ade, adp, asd, asf, asx, bat, chm, cli, cmd, com, cpp, diz, dll, dot, emf,
#   eml, exe, hlp, hsq, hta, ini, js, jse, lnk, mda, mdb, mde, mdw, msi, msp,
#   nws, ocx, pif, pl, pm, pot, pps, ppt, reg, rtf, scr, shs, swf, sys, vb,
#   vbe, vbs, vcf, vxd, wmd, wmf, wms, wmz, wpd, wpm, wps, wpz, wsc, wsf, wsh,
#   xlt, xlw
#

alert tcp $HOME_NET any -> $EXTERNAL_NET 25 (msg:"VIRUS OUTBOUND bad file attachment"; flow:to_server,established; content:"Content-Disposition|3A|"; nocase; pcre:"/filename\s*=\s*.*?\.(?=[abcdehijlmnoprsvwx])(a(d[ep]|s[dfx])|c([ho]m|li|md|pp)|d(iz|ll|ot)|e(m[fl]|xe)|h(lp|sq|ta)|jse?|m(d[abew]|s[ip])|p(p[st]|if|[lm]|ot)|r(eg|tf)|s(cr|[hy]s|wf)|v(b[es]?|cf|xd)|w(m[dfsz]|p[dmsz]|s[cfh])|xl[tw]|bat|ini|lnk|nws|ocx)[\x27\x22\n\r\s]/iR"; classtype:suspicious-filename-detect; sid:721; rev:8;)