<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Ensure its a false positive too. <br><br>Sent from my iPhone</div><div><br>On Oct 26, 2012, at 12:48 PM, "Jefferson, Shawn" <<a href="mailto:Shawn.Jefferson@...14448...">Shawn.Jefferson@...14448...</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">Typo… copying = coping<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Jefferson, Shawn [<a href="mailto:Shawn.Jefferson@...14448...">mailto:Shawn.Jefferson@...14448...</a>] <br><b>Sent:</b> Friday, October 26, 2012 9:37 AM<br><b>To:</b> Joel Esler; K Vijaya Sai Prasanth<br><b>Cc:</b> <a href="mailto:snort-users@...4422...urceforge.net">snort-users@lists.sourceforge.net</a><br><b>Subject:</b> Re: [Snort-users] Signature 17210<o:p></o:p></span></p></div></div><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">As far as false positives go, I think you have the following options (if the traffic/event is legitimate and cannot be shutdown):<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><!--[if !supportLists]--><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">     </span></span></span><!--[endif]--><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">Disable the rule entirely (you will lose all detection/prevention for this rule though!)<o:p></o:p></span></p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><!--[if !supportLists]--><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">     </span></span></span><!--[endif]--><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">Write a suppression rule in threshold.conf (a more targeted approach).<o:p></o:p></span></p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><!--[if !supportLists]--><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">     </span></span></span><!--[endif]--><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">Take the original rule, add some unique content match to it, and make it a pass rule in your local.rules (where you can identity something unique about the false positive and don’t have the ability to do #2 above without losing some detection/prevention capability.)<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">That’s what I do in these cases.  Anyone else have additional ways of copying with false positives?<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p> </o:p></span></p><div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Joel Esler [<a href="mailto:jesler@...843.....1935...">mailto:jesler@...1935...</a>] <br><b>Sent:</b> Friday, October 26, 2012 6:16 AM<br><b>To:</b> K Vijaya Sai Prasanth<br><b>Cc:</b> <a href="mailto:snort-users@lists.sourceforge.net">snort-users@...5870....net</a><br><b>Subject:</b> Re: [Snort-users] Signature 17210<o:p></o:p></span></p></div></div><p class="MsoNormal"><o:p> </o:p></p><div><div><p class="MsoNormal">On Oct 26, 2012, at 6:31 AM, K Vijaya Sai Prasanth <<a href="mailto:sai.prashanth@...15887...">sai.prashanth@...15887...</a>> wrote:<o:p></o:p></p></div><p class="MsoNormal" style="margin-bottom:12.0pt"><o:p> </o:p></p><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Can anyone explain when this rule is triggered and how any false positives can be mitigated? I see that this is the rule definition. Can someone please interpret this?<o:p></o:p></span></p></div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p></div></div><p class="MsoNormal">That rule indicates a Portable Executable file transfer has taken place over SMB shares.<o:p></o:p></p><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">I'd get started with the docs at <a href="http://www.snort.org/docs">www.snort.org/docs</a> for information.<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Lucida Grande"">--</span><br><b><span style="font-size:9.0pt;font-family:"Lucida Grande"">Joel Esler</span></b><br><span style="font-size:9.0pt;font-family:"Lucida Grande"">Senior Research Engineer, VRT</span><br><span style="font-size:9.0pt;font-family:"Lucida Grande"">OpenSource Community Manager</span><br><span style="font-size:9.0pt;font-family:"Lucida Grande"">Sourcefire</span><o:p></o:p></p></div></div></div></blockquote></body></html>