Tagged Questions

Snort is an open source network intrusion detection and prevention system (NIDS/NIPS).

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21 views

Running snort behind iptables

I run a Centos 6.5 server with a highly restrictive iptables ruleset allowing incoming traffic only on a small handful of tcp ports (8 in total) and blocks all incoming unsolicited UDP traffic. I ...
-1
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0answers
18 views

snort per packet content whitelisting how?

What would a snort content whitelisting rule look like? I want to allow a packet as long as its content contains only a certain approved text string and nothing else. Another orthogonal question: ...
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1answer
22 views

Where does Snort log the messages when using a pcap file?

When you're using Snort for real-time monitoring the messages are logged to /var/log/snort/alerts. However, when you load a pcap file, where do you see if any packet triggered a rule? Because they ...
-1
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0answers
21 views

Reducing noise on exe download Snort rule

What is the best way to reduce noise on Snort rules dealing with .exe/.dll downloads from trusted sources? I'm getting a lot of alerts from Windows and Adobe updates, I've been modifying the rule to ...
0
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1answer
38 views

Snort Rule Comparison

As far as I read, Emerging threats and VRT Snort rules are available freely, and also Pro (fee based). Is there any comparision, or anything to suggest choose one over another? What are the benefits ...
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2answers
1k views

Can installing Snort make me vulnerable?

I am using Ubuntu and am wondering if installing Snort on my host can make me more vulnerable?
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3answers
80 views

Is there any hardware solution for IDS?

Are there any products that let you see and set IDS [Intrusion detection system] on router or any another hardware that is connected to the router? All the ones I have found of them are Operating ...
0
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1answer
95 views

How can I test a DoS attack against snort?

I need to set up an scenario where an attacker DoS attacks port 80 of an server while snort and others users try to connect to port 80 at the same time. Something like this: 1000 connections to port ...
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1answer
68 views

What does this Snort rule do? [closed]

Rule-4: alert udp $EXTERNAL_NET any -> $HOME_NET 3333 (msg:"ET EXPLOIT Wireshark ENTTEC DMX Data Processing Code Execution Attempt 1"; content:"|45 53 44 44|"; depth:4; content:"|04|"; ...
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1answer
112 views

SNORT alert for Trufflehunter SFVRT 3:29312:1

I am seeing this Snort alert show up multiple times a day, but my Google-foo is failing me, as I can not find any information about this alert on the internet. Can anyone point me in the direction ...
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2answers
184 views

honeyd is still a good alternative?

I've been investigating to deploy a honeypot for research purpose, Honeyd seems like the most popular and adequate option to my needs, but it seems too old, the last version of this software was ...
0
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2answers
141 views

Can't understand SNORT rule pcre option syntax “?P=name”

While trying to understand some SNORT rule lines, I came across the following syntax that I could not figure. Could not find any description in the manual (though admittedly I've not read it all ...
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1answer
159 views

What shoud I do for solving this problem ? Problem is about SNORT [closed]

Snort, daq and WinPcap are installed. The rule files are located at a convenient place. How can I solve this problem? A clue is the ERROR line: Missing/incorrect dynamic engine lib specifier.
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1answer
36 views

Multi flows snort rule

Is it possible to write a snort rule that match on 2 different flows? For instance on a communication from host-a <--> host-b that happen at the same time as a communication on host-a <--> ...
0
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1answer
176 views

Are my Snort rules correct?

I am trying to do a Snort demo and I though it would be nice to detect a real threat. I picked the sasser worm and the jolt/teardrop dos attacks for the demo; no particular reason. Out of the three ...
4
votes
4answers
512 views

Unicast ARP Requests: Considered Harmful?

I'm playing around with Snort's downloadable rules and I found one which is easy to activate: sending a unicast ARP request. Okay, so I start injecting ARP requests, making sure the destination is not ...
1
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2answers
178 views

How to detect Snort on the network?

Does anyone know how to fingerprint an IPS ? is there any tool available to do the job? I want to detect snort in my network . Would appreciate any kind of help.
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0answers
55 views

Barnyard2 Can't pull xref from unified2 format

I have snort configured to log unified2 in my snort.conf file and am using barnyard2 to parse the unified2 results. It works, except I can seem to figure out to pull the event reference (xref) out of ...
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3answers
96 views

IDS in combination with vulnerability scanner

I'm planning to set up a server environment with high security requirements on which i want to install an intrusion detection system (snort). Additionally, I think of running a vulnerability scanner ...
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0answers
147 views

Snort sfportscan does not log in unified2 file format

I'm running Snort version 2.9.6.0 and I'm not able to log events from the sfportscan preprocessor using the unified2 file format. This is the conf (actually is the default one): preprocessor ...
1
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1answer
234 views

Snort Rule Writing (Alert Fires But Traffic Does Not Match *Intended* Rule)

I have the following rule: alert tcp $HOME_NET any > $EXTERNAL_NET any (msg:"This should not happen"; flow:established,to_server; content:"GET "; depth:4; content:"Set-Cookie:"; http_header; ...
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votes
1answer
142 views

Snort / PulledPork event filter via modifysid.conf not filtering traffic [closed]

I'm using SecurityOnion with Snort/PulledPork/Snorby. I am getting multiple "ET POLICY Pandora Usage" alerts a minute for the same source and destination. I want to threshold these to get 1 alert per ...
4
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3answers
409 views

Log Attacks in Different Files using Snort

How can I log attacks separately using snort. I basically want to log attacks invoked from different files separately. Like if I have 2 files, ddos.rules and log.rules, then I want logs generated from ...
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1answer
293 views

How to use an OR condition with the content of a snort rule

I understand that if you specify multiple contents then the rule triggers only if ALL the content conditions are satisfied. But I want to create a rule that will trigger even if any one of the ...
0
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1answer
57 views

How to log packets which are allowed by SNORT?

Suppose i have not written rule for a type of attack in SNORT; It is obvious that it wont show any alerts. I wanna develop a system wherein i capture packets that SNORT allows n do further processing ...
1
vote
1answer
349 views

Block Packets in snort

In rules Configuration of snort , this is allowed: alert tcp any any -> any any (msg:"HTTP Connection"; react:block;) however when i write this is allowed: alert icmp any any -> any any (msg:"HTTP ...
1
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0answers
207 views

Snort not showing dropped/blocked packets

This question is about SNORT- I m basically trying to detect PING FLOOD attack. I have included the rule**(drop icmp any any -> any any (itype:8; threshold, track by_src, count 20, ...
5
votes
1answer
493 views

Snort alert log simple question

I am analyzing Snort alert log and cannot figure what [1:1071:6] means in 10/12-12:44:28.793118 [**] [1:1071:6] WEB-MISC .htpasswd access [**] [Classification: Web Application Attack] [Priority: 1] ...
0
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1answer
174 views

IDS false positive rates

Are there any industry accepted standards for the false positive rates for a Network IDS based on Snort? Is there a way to check the false positive rates in a deployed IDS? (ideally without looking at ...
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1answer
36 views

Handle snort's rules remotely [closed]

I have multiple snort sensors in my network and i would like to handle the rules of each one remotely. Is there any software that do that ? thanks in advance
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votes
1answer
515 views

Web GUI for Snort + ModSecurity [closed]

I'm trying to find a suitable (or easily modifiable) web GUI for snort + modsecurity logs. As far as I know, Splunk can do that by installing the snort and modsecurity plugins. Is there any other ...
3
votes
1answer
275 views

What is the danger of the “FTP RNFR ././ attempt”?

I am analysing an old attack and I got a scenario which does not really make sense to me. The attacker connects to the ftp service and runs a bunch "FTP RNFR ././ attempt". This is caught by snort as ...
2
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0answers
282 views

Security Onion:snorby alerts shows all local nerwork source IP(public and private)

I have just installed Security Onion distro based on ubuntu. This distro does a great job of combining multiple tools like snort/suricata,sguil,snorby,elsa,bro ids,squert. In my Security Onion ...
2
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1answer
4k views

Snort/IDS detect and alert on possible DoS/DDoS attack?

As per the title, I'm attempting to configure Snort to detect and alert on a incoming Denial of Service attack. Looking at the rulesets, which are primarily signature based rules, I can't see a ...
0
votes
1answer
70 views

How to specify a Snort rule connection duration?

Is it even possible to specify into a snort rule the duration of a connection? For example: in this format Hour, Minute, Second H, M, S = 0, 2, 1 If a connection that has the duration of 2 minutes ...
2
votes
1answer
581 views

How to add wildcards to snort rule ip address?

Is it possible to add wildcards or something that would function like them to a snort rule IP address? For example: If I'd like to detect source-ip of: 192.168.*.9 Where the third octet can be ...
2
votes
1answer
847 views

COMMUNITY SIP TCP/IP message flooding directed to SIP proxy

I have installed Snort IDS and most alarm is: "COMMUNITY SIP TCP/IP message flooding directed to SIP proxy" And i use home DSL Internet connection , should i be worried about this alarm ? I have ...
4
votes
2answers
4k views

Snort (IDS) Don't show Port Scans

I have install Snort & acidbase by this instruction and access it through this local address 127.0.0.1/acidbase/base_main.php The problem is after scan it with nmap by this command sudo ...
2
votes
1answer
612 views

snort ignores packets with matching src/dest IP address

This is my rule: alert udp 192.168.1.1 4000 -> 192.168.1.1 7000 (msg:"This rule doesn't work"; sid:1234567;) I am running snort against a precaptured packet file where there are UDP packets that ...
2
votes
0answers
192 views

Snort Parallelization Techniques and its effect on DDOS detection capability

I want to ask a query about snort parallelization. 1) Can snort detection rate remains same for all attacks after parallelisation? 2) As the parallelisation of netowrk traffic in each core is based ...
3
votes
1answer
1k views

Are Kismet (on OpenWRT) and Snort IDS (on a linux server) compatitble?

I'm trying to develop an IDS/IPS system project to include these elements: A router running OpenWRT running Kismet drone (Attitude Adjustment 12.09rc1) A Linux server (Running Kismet server + client) ...
1
vote
1answer
802 views

Snort, add TCP retransmission rule

Can somebody help me with adding rule for packet retransmission. I found some documentation about the snort rules, but I am confused how to use it. The rules which catches the packet retransmission ...
5
votes
1answer
618 views

Setting up home lab with Snort and Vyatta - looking for resource recommendations or advice

I'm looking to turn a new desktop (Ubuntu 12.10-64bit) I built into a virtual home lab for testing and experimenting with various security things. The first setup I would like to try running is the ...
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2answers
588 views

What type of data does Snort log?

This is new to me, but what types of data does Snort log for Network Intrusion Detection? I am guessing time stamp, source IP address, destination IP address, source port, destination port, protocol. ...
1
vote
1answer
483 views

Are there any test cases to ensure the “web-attacks.rules” snort file works correctly?

I have set up an free evaluation Confluence Server on my local host and have configured "snort.conf" to point to my localhost as "HOME_NET" environment variable. I tried to test the ICMP rule by ...
1
vote
1answer
462 views

How to write Snort rules based on MAC address?

I would like to create Snort rules based on MAC addresses instead of IP addresses. Most devices on the network are DHCP assigned, and I would like to ignore certain traffic (ex: Dropbox) for some ...
2
votes
1answer
173 views

Swatch installation's issue to detect intrusion

I have installed snort and I want to use the swatch tool to send me an email when it detects something going wrong. I am using OSX and I followed the installation guide: ...
0
votes
1answer
841 views

Why aren't anomaly-based intrusion detection schemes implemented in Snort?

I have read many papers on anomaly-based network intrusion detection. Am I correct that each of their techniques could be implemented as Snort preprocessor? If this is true, why there are no anomaly ...
1
vote
3answers
2k views

Using an IPS as an alternative to mod_security

I am considering deploying mod_security as an addition to our web infrastructure. I am worried about the increased load however as these servers get a lot of hits. I am considering using IPS's such ...
2
votes
2answers
352 views

Enterprise IDS - Deployment & Uses

I am investigating deploying the Snort IDS for an enterprise environment. This environment consists of a NOC that manages several servers, mainly internal but some internet facing. There are several ...