Skip to main content

Questions tagged [suricata]

Suricata is a free and open source, mature, fast and robust network threat detection engine.

Filter by
Sorted by
Tagged with
1 vote
1 answer
165 views

ThreatFox alert on Cloudflare IP

On our company network, suricata just raised the following (single) alert: { "timestamp": "2024-01-05T12:42:28.511703+0100", "flow_id": 1276412390854359, &...
Heinzi's user avatar
  • 3,778
1 vote
1 answer
161 views

Snort / Suricata rules from HOME_NET with rule option flow:to_client

Reading through Suricata/Snort IDS rules, I can see examples such as below, and scratching my head to understand how is it feasible that a connection from home_network to external_network can have a ...
RGC's user avatar
  • 11
0 votes
0 answers
90 views

Suricata 6.x not decoding MPLS packets

Manuals say modern Suricata supports decoding GRE/MPLS/etc by default. My config file uses all the CPU cores with normal traffic. However, during analyzing MPLS traffic only 1 core is 100% busy and ...
alexoy's user avatar
  • 1
1 vote
1 answer
929 views

I am noticing a malicious DNS query in Thunderbird

My Suricata IDS is generating this alert when starting Thunderbird: ET INFO Observed DNS Query to .cloud TLD You can analyze a json log: { "_index": "suricata-1.1.0-2022.02.11", ...
Ecofintech's user avatar
2 votes
1 answer
425 views

What is the best way to create a PCAP file containing malicious traffic?

I'm in my last year of university and for my honour's project I am tasked with comparing two intrusion detection systems, snort and suricata, hosted on a virtual machine on my PC. As I have no access ...
Conor's user avatar
  • 21
0 votes
1 answer
1k views

suricata http rule to identify POST requests

I can’t figure it out / understand. Need to write a rule that catches an HTTP POST request from one ip address more than three times in 10 seconds and logs it. alert http $EXTERNAL_NET any -> $...
Norfo4ik's user avatar
  • 101
1 vote
0 answers
190 views

Can I write a suricata rule based on the timestamp the packet arrives on the host?

We have a need to check the arrival time of two relative packets, like packet1 and packet2, if packet2 arrives too late after packet1, we want an alert for it. Is it possible to write a rule for this? ...
cifer's user avatar
  • 111
0 votes
1 answer
3k views

Suricata - How to use TCP Flags?

I wrote the following rules: alert tcp any any -> 192.168.6.4 any (msg:"SYN"; flags: S;) alert tcp any any -> 192.168.6.4 any (msg:"FIN"; flags: F;) The SYN rule is matching....
flippie's user avatar
0 votes
1 answer
243 views

Help in Suricata rule bitmask syntax problem

I have written the following rule in my Suricata rules file: alert tcp any any <> any any (flow:established; content:"|65|"; offset:0; depth:1; byte_test:1, =, 3, 2, bitmask 0x03; msg:&...
Khalid's user avatar
  • 303
0 votes
1 answer
339 views

Suricata Ripple20 rule for IP-in-IP resulting in 100M alerts

I found too many events in Suricata after recent update regarding this rule: alert ip any any -> any any (msg:"ET EXPLOIT Possible CVE-2020-11900 IP-in-IP tunnel Double-Free"; ip_proto:4; ...
Giac's user avatar
  • 175
1 vote
1 answer
1k views

Suricata and rules based on MAC address

I'm working on a project to implement SDN in a network. One of my flows is redirecting to the Suricata IDS and the flow works in layer 2 with MAC address. Since I've read that Snort only works in ...
loi219's user avatar
  • 113
1 vote
1 answer
656 views

Suricata bypass keyword

I have not found any examples on using the 'bypass' keyword. Does it work in any rule? Are there performance implications using 'bypass'. For example, would this bypass all tcp traffic? alert tcp any ...
dcol's user avatar
  • 11
0 votes
1 answer
484 views

Suricata not matching a packet

What happens to a packet that has no matching rule in Suricata. I assume it is ignored, but haven't found any definitive info on this. So, if my assumption is correct and the packet is ignored, would ...
dcol's user avatar
  • 11
1 vote
1 answer
2k views

Custom Suricata's HTTP alert isn't triggered when using ".." as part of the scanned uri. Why? [closed]

I have a doubt with a Suricata custom rule. If I do: alert http any any -> any 80 (msg:"blabla"; content:"abc"; http_uri; sid:1000000;) I can get requests to http://x.x.x.x/abc uri in fast.log ...
Osqui's user avatar
  • 113
0 votes
1 answer
1k views

Loopback with Suricata

Is there any way of analyzing loopback traffic with Suricata? I am trying it this way without success: root@security-onion:/home/sar/TFM/alerts/suricata# suricata -c /etc/suricata/suricata.yaml -i ...
Neveralways's user avatar
0 votes
1 answer
1k views

Analyzing Apache log with Snort

I need to analyze an Apache log with Snort and others IDS/WAFs (Suricata, mod_security and Shadow Daemon). In order to do so, I was thinking about create TCP packets with the GET and POST requests ...
Neveralways's user avatar
0 votes
1 answer
2k views

Virustotal detecting threats in Suricata rule set

Virustotal scans are detecting threats from the Suricata default rule pack located https://rules.emergingthreats.net/open/suricata-4.0/ Is this a false positive? https://www.virustotal.com/#/file/...
calk93's user avatar
  • 1
4 votes
0 answers
1k views

How can I get Suricata to alert on 1 packet every time

I am trying to write a Suricata signature for testing purposes to alert every time it is triggered with a single PCAP file containing a single packet, but this is proving to be harder than I thought. ...
MikeSchem's user avatar
  • 2,351