fox-srt

# Signatures for detecting Microsoft Word Intruder
# https://www.fireeye.com/blog/threat-research/2015/04/a_new_word_document.html

alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"FOX-SRT - Trojan - Microsoft Word Intruder payload request"; content:"GET"; depth:3; flowbits:set,mwi; content:!"Referer|3a| "; content:!"Cookie|3a| "; uricontent:"&act=1"; fast_pattern: only; pcre:"/\/webstat\/image\.php\?id=[0-9]{8}/"; threshold: type limit, track by_src, count 1, seconds 3600; classtype:trojan-activity; reference:url,https://www.fireeye.com/blog/threat-research/2015/04/a_new_word_document.html; sid:21001609; rev:1;)

alert tcp $EXTERNAL_NET $HTTP_PORTS -> $HOME_NET any (msg:"FOX-SRT - Trojan - Microsoft Word Intruder payload response"; flowbits:isset,mwi; content:"Content-Type|3a| application/octet-stream"; content:"Content-Description|3a| File Transfer"; pcre:"/filename=[0-9]{8}\.exe/"; threshold: type limit, track by_src, count 1, seconds 3600; classtype:trojan-activity; reference:url,https://www.fir

fox-srt

# Signatures to detect successful abuse of the Juniper backdoor password over telnet.
# Additionally a signature for detecting world reachable ScreenOS devices over SSH.

alert tcp $HOME_NET 23 -> any any (msg:"FOX-SRT - Flowbit - Juniper ScreenOS telnet (noalert)"; flow:established,to_client; content:"Remote Management Console|0d0a|"; offset:0; depth:27; flowbits:set,fox.juniper.screenos; flowbits:noalert; reference:cve,2015-7755; reference:url,http://kb.juniper.net/JSA10713; classtype:policy-violation; sid:21001729; rev:2;)
alert tcp any any -> $HOME_NET 23 (msg:"FOX-SRT - Backdoor - Juniper ScreenOS telnet backdoor password attempt"; flow:established,to_server; flowbits:isset,fox.juniper.screenos; flowbits:set,fox.juniper.screenos.password; content:"|3c3c3c20257328756e3d2725732729203d202575|"; offset:0; fast_pattern; classtype:attempted-admin; reference:cve,2015-7755; reference:url,http://kb.juniper.net/JSA10713; sid:21001730; rev:2;)
alert tcp $HOME_NET 23 -> any any (msg:"FOX-SRT - Backdoor - Juniper Scr

fox-srt

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            b3:41:c8:fd:5c:fa:8f:a5
    Signature Algorithm: sha1WithRSAEncryption
        Issuer: C=XX, ST=1, L=1, O=1, OU=1, CN=107.181.187.182/[email protected]
        Validity
            Not Before: Jun  4 10:15:01 2016 GMT
            Not After : Jun  4 10:15:01 2017 GMT

fox-srt

alert tcp $EXTERNAL_NET any -> $HOME_NET 7547 (msg:"FOX-SRT – Exploit – TR-069 SOAP RCE NewNTPServer exploit incoming"; flow:established,to_server; content:"POST"; depth:4; content:"/UD/act?1"; content:"urn:dslforum-org:service:Time:1#SetNTPServers"; threshold: type limit, track by_dst, count 1, seconds 60; classtype:attempted-admin; reference:url,blog.fox-it.com/2016/11/28/recent-vulnerability-in-eir-d1000-router-used-to-spread-updated-version-of-mirai-ddos-bot; sid:1; rev:1;)
alert tcp $HOME_NET any -> $EXTERNAL_NET 7547 (msg:"FOX-SRT – Exploit – TR-069 SOAP RCE NewNTPServer exploit outgoing"; flow:established,to_server; content:"POST"; depth:4; content:"/UD/act?1"; content:"urn:dslforum-org:service:Time:1#SetNTPServers"; threshold: type limit, track by_src, count 1, seconds 60; classtype:attempted-admin; reference:url,blog.fox-it.com/2016/11/28/recent-vulnerability-in-eir-d1000-router-used-to-spread-updated-version-of-mirai-ddos-bot; sid:2; rev:1;)

fox-srt

# IDS Signatures to detect Ticketbleed (CVE-2016-9244)
# https://blog.fox-it.com/2017/02/13/detecting-ticketbleed-cve-2016-9244/

alert tcp $EXTERNAL_NET any -> $HOME_NET [$HTTP_PORTS,443] (msg:"FOX-SRT - Flowbit - TLS session resumption < 32 byte session id (noalert)"; flow:established,to_server; content:"|1603|"; depth:2; content:"|01|"; distance:3; within:1; byte_test:3,<,3000,0,relative; content:"|03|"; distance:3; within:1; byte_test:1,<,32,33,relative; byte_test:1,>,0,33,relative; flowbits:set,fox.ticketbleed.session; flowbits:noalert; threshold:type limit, track by_src, count 1, seconds 600; classtype:attempted-recon; reference:cve,2016-9244; reference:url,https://ticketbleed.com; reference:url,blog.fox-it.com/2017/02/13/detecting-ticketbleed-cve-2016-9244; sid:21002061; rev:6;)
alert tcp $HOME_NET [$HTTP_PORTS,443] -> $EXTERNAL_NET any (msg:"FOX-SRT - Vulnerability - Possible Succesful F5 Big-IP TLS Ticketbleed"; flow:established,to_client; flowbits:isset,fox.ticketbleed.session; content:"|1603|"; dep

fox-srt

#!/usr/bin/env python
"""
Netsarang backdoor DNS payload decrypter

file:     decode_shadowpad_dns.py
author:   Fox-IT Security Research Team <[email protected]>

 Usage: 
   $ cat dns.txt
   sajajlyoogrmkllmuoqiyaxlymwlvajdkouhkdyiyolamdjivho.cjpybuhwnjgkhllm.nylalobghyhirgh.com

fox-srt

# Snort & Suricata signatures for:
# https://blog.fox-it.com/2018/01/11/mitm6-compromising-ipv4-networks-via-ipv6

alert udp fe80::/12 [546,547] -> fe80::/12 [546,547] (msg:"FOX-SRT - Policy - DHCPv6 advertise"; content:"|02|"; offset:48; depth:1; reference:url,blog.fox-it.com/2018/01/11/mitm6-compromising-ipv4-networks-via-ipv6/; threshold:type limit, track by_src, count 1, seconds 3600; classtype:policy-violation; sid:21002327; rev:2;)
alert udp ::/0 53 -> any any (msg:"FOX-SRT - Suspicious - WPAD DNS reponse over IPv6"; byte_test:1,&,0x7F,2; byte_test:2,>,0,6; content:"|00 04|wpad"; nocase; fast_pattern; threshold: type limit, track by_src, count 1, seconds 1800; reference:url,blog.fox-it.com/2018/01/11/mitm6-compromising-ipv4-networks-via-ipv6/; classtype:attempted-admin; priority:1; sid:21002330; rev:1;)

fox-srt

# IDS signatures for https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180129-asa1:
alert udp any any -> any 500 (msg:"FOX-SRT - Suspicious - Possible Fragmented Cisco IKE/isakmp Packet HeapSpray (CVE-2018-0101)"; flow:to_server; content:"|84|"; offset:16; depth:1; content:"|02|"; distance:1; within:1; fast_pattern; byte_test:4,>,5000,5,relative; byte_test:2,>,5000,11,relative; byte_extract:4,36,fragment_match; byte_test:4,=,fragment_match,53,relative; byte_test:4,=,fragment_match,137,relative; byte_test:4,=,fragment_match,237,relative; threshold:type limit, track by_dst, count 1, seconds 600; classtype:attempted-admin; sid:21002339; rev:5;)
alert udp any any -> any 500 (msg:"FOX-SRT - Exploit - Possible Shellcode in Cisco IKE/isakmp - tcp/CONNECT/"; content:"tcp/CONNECT/"; fast_pattern:only; threshold:type limit, track by_src, count 1, seconds 600; priority:1; classtype:attempted-admin; sid:21002340; rev:2;)

fox-srt

alert tcp any any -> any any (msg:"FOX-IT - Trojan - Possible CobaltStrike C2 Server"; \
    flow:to_client; \
    content:"HTTP/1.1 200 OK |0d0a|"; fast_pattern; depth:18; \
    content:"Date: "; \
    pcre:"/^HTTP/1.1 200 OK \r\nContent-Type: [^\r\n]{0,100}\r\nDate: [^\r\n]{0,100} GMT\r\n(Content-Length: \d+\r\n)\r\n/"; \
    threshold:type limit, track by_dst, count 1, seconds 600; \
    classtype:trojan-activity; priority:2; \
    sid:21002217; rev:3;)

fox-srt

# Detects Log4j exploitation attempts
alert http any any -> $HOME_NET any (msg:"FOX-SRT - Exploit - Possible Apache Log4J RCE Request Observed (CVE-2021-44228)"; flow:established, to_server; content:"${jndi:ldap://"; fast_pattern:only; flowbits:set, fox.apachelog4j.rce; threshold:type limit, track by_dst, count 1, seconds 3600; classtype:web-application-attack; priority:3; reference:url, www.lunasec.io/docs/blog/log4j-zero-day/; metadata:CVE 2021-44228; metadata:created_at 2021-12-10; metadata:ids suricata; sid:21003726; rev:1;) 

alert http any any -> $HOME_NET any (msg:"FOX-SRT - Exploit - Possible Apache Log4J RCE Request Observed (CVE-2021-44228)"; flow:established, to_server; content:"${jndi:"; fast_pattern; pcre:"/\$\{jndi\:(rmi|ldaps|dns)\:/"; flowbits:set, fox.apachelog4j.rce; threshold:type limit, track by_dst, count 1, seconds 3600; classtype:web-application-attack; priority:3; reference:url, www.lunasec.io/docs/blog/log4j-zero-day/; metadata:CVE 2021-44228; metadata:created_at 2021-12-10; metadata: