Ransomware incident artifacts comprise the digital traces left by encryption malware on hosts, networks, and backups, enabling investigators to reconstruct attack timelines, identify variants, and scope impact in computer and cyber forensics examinations.
These indicators range from ransom notes and file extensions to shadow copy deletions and exfiltration logs, distinguishing ransomware from other malware through its focus on data denial and extortion.
Analysis of these artifacts supports decryption feasibility, attribution to groups, and prevention of recurrence, critical in modern incidents where multi-extortion tactics amplify damage.
File System and Encryption Markers
Ransomware characteristically modifies files en masse, leaving patterned artifacts across volumes.
Encrypted files gain double extensions (.encrypted, .lockbit); ransom notes (README.txt, HOW_TO_DECRYPT.html) drop in affected directories with actor branding.
Partial encryption (first 1MB untouched) aids variant identification. Mutexes like Global\LockBit or random strings prevent multiple infections.
Timestamps cluster during encryption waves; correlate with process creation.
Volume Shadow Copy and Backup Tampering
Attackers target recovery mechanisms early in kill chains.
Vssadmin delete shadows /quiet removes Windows Shadow Copies; wmic shadowcopy delete confirms. Linux: rm -rf /var/lib/vz/dump erases backups. Event logs (ID 7045 services, 4673 privilege use) precede deletions.
Immutable backups resist; remnants in $Recycle.Bin show attempts.
Persistence and Execution Traces
Linux: Cron jobs, systemd services for persistence.
Network and Exfiltration Indicators
Modern ransomware exfils data pre-encryption.
NetFlow volume spikes to leak sites; DNS queries to C2 domains. PCAPs reveal staged uploads (ZIP archives). EDR logs show Cobalt Strike beacons preceding encryption.
Host and Registry Footprints
System changes facilitate operations.
New services (sc query shows recent installs); explorer.exe anomalies from network shares. Registry: RecentDocs, UserAssist track RDP dropper execution. USBSTOR entries indicate air-gapped spread.
PowerShell Operational logs (4104 modules) reveal scripting.
Analysis Workflow and Attribution
Structured examination maps lifecycle.
Challenges: Wipers erase traces; live response captures volatiles first.
