Penetration Testing mailing list archives
RE: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket
From: "Robert E. Lee" <robert () dyadsecurity com>
Date: Mon, 26 Apr 2004 09:25:01 -0700
You have to do your logistics and control testing before launching any type of massive tool like nessus. Without doing this type of testing ahead of time, no matter how many times you run any VA tool, your results will always be incomplete and invalid. Furthermore, I would not recommend using nessus to enumerate systems/ports/services for you. I would do all of that through other means for accuracy and completeness and then feed that reconnaissance data into Nessus (and at least one additional VA tool). Breaking that stuff away from Nessus allows for MUCH more thorough and accurate results. It also allows you to do additional researching while your VA tools hammer away. For more details of what I'm talking about, pull down the OSSTMM from http://www.osstmm.org. You can see the Logistics and Control module from Section C. You'll also find good enumeration techniques here. TCP syn scanning is really well done with scanrand2 (you can pull down pre3 from http://www.doxpara.com). I like sing and xprobe for icmp scanning. There just isn't a good udp scanner out there yet (because of the nature of how UDP works), especially for sites that block icmp on egress. The best thing I've found to do in those situations is to script specific queries from the well known set of udp based protocols (snmp, dns, isakmp, ntp, a list of Trojans, etc, etc, etc). For the more exotic port scanning techniques out there nmap is pretty flexible, but its speed and interface make it a better checkup tool rather than an enterprise scanner. Happy testing, Robert -----Original Message----- From: Brass, Phil (ISS Atlanta) [mailto:PBrass () iss net] Sent: Sunday, April 25, 2004 2:17 PM To: Paul Johnston; pen-test () securityfocus com Subject: RE: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket
1) How reliable have people here found nmap and nessus to be? I have encountered (rare) cases of nmap not finding ports, and also of nessus not identifying ports during the find_service stage. We hear a lot about false positives, but it's much harder to notice false negatives. Anything that can be done about this?
Assuming that it's not an actual bug in the scanning product, just run the scan a few times. Take the superset of all scan results. Three or four times should usually get to the point of diminishing returns as far as finding new things, unless you've got poorly configured timeouts or are using more bandwidth than is available... Phil ------------------------------------------------------------------------ ------ Ethical Hacking is a joke. Anyone who sells "Ethical Hacking" classes is selling garbage. Mention this ad and get $545 off any course! All of our class sizes are guaranteed to be 10 students or less to facilitate one-on-one interaction with one of our expert instructors. Attend a course taught by an expert instructor with years of in-the-field pen testing experience in our state of the art hacking lab. Master the skills of an Ethical Hacker to better assess the security of your organization. Visit us at: http://www.infosecinstitute.com/courses/ethical_hacking_training.html ------------------------------------------------------------------------ ------- ------------------------------------------------------------------------------ Ethical Hacking at the InfoSec Institute. Mention this ad and get $545 off any course! All of our class sizes are guaranteed to be 10 students or less to facilitate one-on-one interaction with one of our expert instructors. Attend a course taught by an expert instructor with years of in-the-field pen testing experience in our state of the art hacking lab. Master the skills of an Ethical Hacker to better assess the security of your organization. Visit us at: http://www.infosecinstitute.com/courses/ethical_hacking_training.html -------------------------------------------------------------------------------
Current thread:
- Re: Web site testing, (continued)
- Re: Web site testing Dan Goldberg (Apr 23)
- RE: Web site testing Jerry Shenk (Apr 23)
- RE: Web site testing Clement Dupuis (Apr 26)
- Re: Web site testing Dan Goldberg (Apr 23)
- Re: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket Anders Thulin (Apr 27)
- Re: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket James Davis (Apr 30)
- Re: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket Renaud Deraison (Apr 30)
- Re: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket Don Parker (Apr 23)
- RE: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket Brass, Phil (ISS Atlanta) (Apr 26)
- RE: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket Robert E. Lee (Apr 26)
- RE: Questions: nmap, nessus unreliability, setting up a packet capture box, using Impacket BĂ©noni MARTIN (Apr 30)