- IDS
- Intrusion Detection System (signature based (eg. snort) or behaviour based).
- Snort/Suricata/YARA rule writing
- Host-based Intrusion Detection System (eg. OSSEC)
- SIEM
- Security Information and Event Management.
- IOC
- Indicator of compromise (often shared amongst orgs/groups).
- Specific details (e.g. IP addresses, hashes, domains)
- Security Signals
- Things that create signals
- Honeypots, snort.
- Things that triage signals
- SIEM, e.g. splunk.
- Things that will alert a human
- Automatic triage of collated logs, machine learning.
- Notifications and analyst fatigue.
- Systems that make it easy to decide if alert is actual hacks or not.
- Things that create signals
- Signatures
- Host-based signatures
- E.g. changes to the registry, files created or modified.
- Strings in found in malware samples appearing in binaries installed on hosts (/Antivirus).
- Network signatures
- E.g. checking DNS records for attempts to contact C2 (command and control) servers.
- Host-based signatures
- Anomaly or Behavior Based Detection
- IDS learns model of “normal” behaviour, then can detect things that deviate too far from normal
- E.g. unusual urls being accessed, user specific
- login times / usual work hours, normal files accessed.
- Can also look for things that a hacker might specifically do (eg, HISTFILE commands, accessing /proc).
- If someone is inside the network- If action could be suspicious, increase log verbosity for that user.
- IDS learns model of “normal” behaviour, then can detect things that deviate too far from normal
- Firewall Rules
- Brute force (trying to log in with a lot of failures).
- Detecting port scanning (could look for TCP SYN packets with no following SYN ACK/ half connections).
- Antivirus software notifications.
- Large amounts of upload traffic.
- Honeypots
- Canary tokens.
- Dummy internal service / web server, can check traffic, see what attacker tries.
- Things to Know About Attackers
- Slow attacks are harder to detect.
- Attacker can spoof packets that look like other types of attacks, deliberately create a lot of noise.
- Attacker can spoof IP address sending packets, but can check TTL of packets and TTL of reverse lookup to find spoofed addresses.
- Correlating IPs with physical location (is difficult and inaccurate often).
- Logs to Look at
- DNS queries to suspicious domains.
- HTTP headers could contain wonky information.
- Metadata of files (eg. author of file) (more forensics?).
- Traffic volume.
- Traffic patterns.
- Execution logs.
- Detection Related Tools
- Splunk.
- Arcsight.
- Qradar.
- Darktrace.
- Tcpdump.
- Wireshark.
- Zeek.
- A curated list of awesome threat detection resources