add multithreaded suricata search code, fetching ids rules based on parameters and terms

examples/suricata_search/README.md

@@ -0,0 +1,24 @@
+# Description
+Get all attributes, from a MISP (https://github.com/MISP) instance, that can be converted into Suricata rules, given a *parameter* and a *term* to search
+
+**requires**
+* PyMISP (https://github.com/CIRCL/PyMISP/)
+* python 2.7 or python3 (suggested)
+
+
+ # Usage
+ * **suricata_search.py -p tags -s 'APT' -o misp_ids.rules -t 5**
+    - search for 'APT' tag
+    - use 5 threads while generating IDS rules
+    - dump results to misp_ids.rules
+    
+ * **suricata_search.py -p tags -s 'APT' -o misp_ids.rules -ne 411 357 343**
+    - same as above, but skip events ID 411,357 and 343
+    
+ * **suricata_search.py -p tags -s 'circl:incident-classification="malware", tlp:green' -o misp_ids.rules**
+    - search for multiple tags 'circl:incident-classification="malware", tlp:green'
+    
+ * **suricata_search.py -p categories -s 'Artifacts dropped' -t 20 -o artifacts_dropped.rules**
+    - search for category 'Artifacts dropped'
+    - use 20 threads while generating IDS rules
+    - dump results to artifacts_dropped.rules

examples/suricata_search/suricata_search.py

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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import argparse
+import os
+import queue
+import sys
+from threading import Thread, enumerate
+from keys import misp_url, misp_key, misp_verifycert
+
+try:
+    from pymisp import PyMISP
+except ImportError as err:
+    sys.stderr.write("ERROR: {}\n".format(err))
+    sys.stderr.write("\t[try] with pip install pymisp\n")
+    sys.stderr.write("\t[try] with pip3 install pymisp\n")
+    sys.exit(1)
+
+
+HEADER = """
+#This part might still contain bugs, use and your own risk and report any issues.
+#
+# MISP export of IDS rules - optimized for suricata
+#
+# These NIDS rules contain some variables that need to exist in your configuration.
+# Make sure you have set:
+#
+# $HOME_NET	- Your internal network range
+# $EXTERNAL_NET - The network considered as outside
+# $SMTP_SERVERS - All your internal SMTP servers
+# $HTTP_PORTS   - The ports used to contain HTTP traffic (not required with suricata export)
+# 
+"""
+
+# queue for events matching searched term/s
+IDS_EVENTS = queue.Queue()
+
+# queue for downloaded Suricata rules
+DOWNLOADED_RULES = queue.Queue()
+
+# Default number of threads to use
+THREAD = 4
+
+try:
+    input = raw_input
+except NameError:
+    pass
+
+
+def init():
+    """ init connection to MISP """
+    return PyMISP(misp_url, misp_key, misp_verifycert, 'json')
+
+
+def search(misp, quiet, noevent, **kwargs):
+    """ Start search in MISP """
+
+    result = misp.search(**kwargs)
+
+    # fetch all events matching **kwargs
+    track_events = 0
+    skip_events = list()
+    for event in result['response']:
+        event_id = event["Event"].get("id")
+        track_events += 1
+
+        to_ids = False
+        for attribute in event["Event"]["Attribute"]:
+            to_ids_event = attribute["to_ids"]
+            if to_ids_event:
+                to_ids = True
+                break
+
+        # if there is at least one eligible event to_ids, add event_id
+        if to_ids:
+            # check if the event_id is not blacklisted by the user
+            if isinstance(noevent, list):
+                if event_id not in noevent[0]:
+                    to_ids_event = (event_id, misp)
+                    IDS_EVENTS.put(to_ids_event)
+                else:
+                    skip_events.append(event_id)
+            else:
+                to_ids_event = (event_id, misp)
+                IDS_EVENTS.put(to_ids_event)
+
+    if not quiet:
+        print ("\t[i] matching events: {}".format(track_events))
+        if len(skip_events) > 0:
+            print ("\t[i] skipped {0} events -> {1}".format(len(skip_events),skip_events))
+        print ("\t[i] events selected for IDS export: {}".format(IDS_EVENTS.qsize()))
+
+
+def collect_rules(thread):
+    """ Dispatch tasks to Suricata_processor worker """
+
+    for x in range(int(thread)):
+        th = Thread(target=suricata_processor, args=(IDS_EVENTS, ))
+        th.start()
+
+    for x in enumerate():
+        if x.name == "MainThread":
+            continue
+        x.join()
+
+
+def suricata_processor(ids_events):
+    """ Trigger misp.download_suricata_rule_event """
+
+    while not ids_events.empty():
+        event_id, misp = ids_events.get()
+        ids_rules = misp.download_suricata_rule_event(event_id).text
+
+        for r in ids_rules.split("\n"):
+            # skip header
+            if not r.startswith("#"):
+                if len(r) > 0: DOWNLOADED_RULES.put(r)
+
+
+def return_rules(output, quiet):
+    """ Return downloaded rules to user """
+
+    rules = set()
+    while not DOWNLOADED_RULES.empty():
+        rules.add(DOWNLOADED_RULES.get())
+
+    if output is None:
+
+        if not quiet:
+            print ("[+] Displaying rules")
+
+        print (HEADER)
+        for r in rules: print (r)
+        print ("#")
+
+    else:
+
+        if not quiet:
+            print ("[+] Writing rules to {}".format(output))
+            print ("[+] Generated {} rules".format(len(rules)))
+
+        with open(output, 'w') as f:
+            f.write(HEADER)
+            f.write("\n".join(r for r in rules))
+            f.write("\n"+"#")
+
+
+def format_request(param, term, misp, quiet, output, thread, noevent):
+    """ Format request and start search """
+
+    kwargs = {param: term}
+
+    print ("[+] Searching for: {}".format(kwargs))
+    search(misp, quiet, noevent, **kwargs)
+
+    # collect Suricata rules
+    collect_rules(thread)
+
+
+if __name__ == "__main__":
+
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawTextHelpFormatter,
+        description='Get all attributes that can be converted into Suricata rules, given a parameter and a term to '
+                    'search.',
+        epilog='''
+        EXAMPLES:
+            suricata_search.py -p tags -s 'APT' -o misp_ids.rules -t 5
+            suricata_search.py -p tags -s 'APT' -o misp_ids.rules -ne 411 357 343
+            suricata_search.py -p tags -s 'tlp:green, OSINT' -o misp_ids.rules
+            suricata_search.py -p tags -s 'circl:incident-classification="malware", tlp:green' -o misp_ids.rules
+            suricata_search.py -p categories -s 'Artifacts dropped' -t 20 -o artifacts_dropped.rules
+        ''')
+    parser.add_argument("-p", "--param", required=True, help="Parameter to search (e.g. categories, tags, org, etc.).")
+    parser.add_argument("-s", "--search", required=True, help="Term/s to search.")
+    parser.add_argument("-q", "--quiet", action='store_true', help="No status messages")
+    parser.add_argument("-t", "--thread", required=False, help="Number of threads to use", default=THREAD)
+    parser.add_argument("-ne", "--noevent", nargs='*', required=False, dest='noevent', action='append',
+                        help="Event/s ID to exclude during the search")
+    parser.add_argument("-o", "--output", help="Output file",required=False)
+
+    args = parser.parse_args()
+
+    if args.output is not None and os.path.exists(args.output):
+        try:
+            check = input("[!] Output file {} exists, do you want to continue [Y/n]? ".format(args.output))
+            if check not in ["Y","y"]:
+                exit(0)
+        except KeyboardInterrupt:
+            sys.exit(0)
+
+    if not args.quiet:
+        print ("[i] Connecting to MISP instance: {}".format(misp_url))
+
+    print ("[i] Note: duplicated IDS rules will be removed")
+
+    # Based on # of terms, format request
+    if "," in args.search:
+        for term in args.search.split(","):
+            term = term.strip()
+            misp = init()
+            format_request(args.param, term, misp, args.quiet, args.output, args.thread, args.noevent)
+    else:
+        if not args.quiet:
+            misp = init()
+            format_request(args.param, args.search, misp, args.quiet, args.output, args.thread, args.noevent)
+
+    # return collected rules
+    return_rules(args.output, args.quiet)