From f4f6fa119a90270bdcb2761871dc3ec23720ce82 Mon Sep 17 00:00:00 2001 From: Jef Roosens Date: Wed, 1 Jan 2025 12:33:13 +0100 Subject: [PATCH] ch08 --- 08_digital_forensics.md | 112 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 08_digital_forensics.md diff --git a/08_digital_forensics.md b/08_digital_forensics.md new file mode 100644 index 0000000..49e6120 --- /dev/null +++ b/08_digital_forensics.md @@ -0,0 +1,112 @@ +# Digital forensics + +* branch of forensic science focused on recovery, investigation, analysis of + material on digital devices +* goal: uncover and preserve digital evidence +* pillars + * **identification**: recognize potential sources of evidence (computers, + phones...) + * **preservation**: ensure digital evidence is protected from tampering + (e.g. taking disk images) + * **analysis**: examine evidence to extract information + * **documentation**: keep detailed records of all actions done during + investigation + * **presentation**: report findings in a clear way + +## Types of devices + +1. computers and laptops: disk image made, analyse for files, browser history, + metadata... +2. smartphones and tablets: call logs, messages, GPS, cloud data... +3. network devices and servers: logged/real-time network traffic +4. IoT devices: configuration, certificates, user interaction data +5. wearables: user profile, GPS data +6. drones: telemetry data, video/photos +7. vehicles: onboard computers contain lots of information (engine control, + navigation...) +8. medical devices: patient health data, usage logs... +9. CCTVs: video footage, access logs +10. device memory (RAM): memory of running processes, network connections... +11. gaming consoles: personal user info, communication (chat logs) +12. cloud storage: files and data + +## Cyber-incident response process + +Secure. Contain. Protect. + +1. preparation: identify risk, plan for threats, training +2. incident identification + * event monitoring, alerting, threat analysis + * identify stage attackers are in +3. containment / intelligence development +4. eradication / remediation + * harden entrypoints / patch + * purge malicious files +5. recovery: restore from backups; get back to safe state +6. improvement + * report on what happened + * update training + +### indicators of compromise + +* evidence that points to breach +* some examples + 1. unusual network traffic + 2. suspicious file activity: malware signatures, unauthorized file creation + 3. abnormal user behavior + 4. system performance anomalies + 5. log file entries: weird stuff in logs, basically all of this but in the + logs + 6. malicious emails + 7. changes in configuration + 8. unauthorized access attempts + 9. indicators in memory and processes + 10. external device connections + 11. anomalies in data exfiltration + * unusual outbound data transfers + * use of non-standard ports or encrypted channels + 12. DNS anomalies + * queries to known malicious domains + * sudden spike + * unusual traffic patterns + +### Indicator sharing languages + +* **[STIX](https://oasis-open.github.io/cti-documentation/)**: Structured + threat Information Expression +* **[MISP XML and JSON](https://github.com/MISP/MISP)** +* transport protocols + * Traffic Light Protocol (TLP) + * TAXII: HTTPS exchange of STIX info +* Yara and Yara-X: pattern matching tools for malware identification +* MISP + * open framework for sharing IoC information + +### Indicator of attack + +* newer cousin of IoC +* proactive +* tries to identify intent of attacker regardless of exploit used +* nowadays lots of malware is signed with legit certificate + * bought from lax CAs + * by setting up fake company + * stealing certificates +* entropy as indicator: measure of randomness in system + * malware packs, compresses, encrypts and obfuscates + * this greatly increases entropy in file + * entropy calculation can be used to detect malware +* tools + * pestudio: static file analysis tool + * cuckoo sandbox: sandbox environment to analyse malware + * redline: tool to analyse processes and file handles on host + * Process Hacker: visual overview of running processes; inspect memory + * ProcMon: record live process activity + * ProcDot: graphical presentation of ProcMon data + * Fiddler: acts like web proxy to analyse HTTP(S) traffic +* forensic tools + * Encase: tool to find case evidence on devices + * FTK: forensic toolkit + * X-Ways Forensics: can restore deleted files + * Sleuth-Kit and Autopsy: disk image investigation + * Volatility: toolkit for investigation RAM to extract data + * create RAM dump