malware-triage

Objective

The primary goal of this initial malware triage was to rapidly determine the file's malicious intent and map its core functionalities by performing non-execution static analysis and leveraging threat intelligence for behavioral mapping. This process mimics the high-priority initial assessment carried out by a Security Operations Center (SOC) analyst when a suspicious file is flagged.

Skills Learned

• Static Analysis Triage: Rapidly assessing a file's reputation and metadata using remote, safe tools.
• Hash and Signature Identification: Generating and verifying the SHA256 hash against major threat intelligence platforms (VirusTotal, MalwareBazaar).
• File Metadata Interpretation: Extracting compiler, linker, and file type information (PE32) to infer the threat developer's environment.
• Threat Intelligence Pivoting: Correlating vendor detection names (Dridex, Zempack) to identify the malware family and its known capabilities.
• Threat Mapping: Translating the required user interaction into an industry-standard technique using the MITRE ATT&CK framework.

Tools Used

• VirusTotal: For reputation checking, static file details, and vendor classification.
• MalwareBazaar: For contextual threat intelligence and hash validation.
• MITRE ATT&CK Knowledge Base: For mapping the execution chain to a specific technique ID.

Steps

Step 1. Initial Hash Validation and Artifact Extraction

Ref 1: MalwareBazaar Database

• Validated the SHA256 Hash against MalwareBazaar, confirming the file's presence and reputation within a critical threat intelligence database..
• Identified the Malware Family as Dridex based on the consensus tagging, enabling rapid context gathering and initial classification.
• the enduser is instructed to click a button that will "report the user".
• Extracted Core IOCs (Indicators of Compromise), including the MD5 and SHA hashes, and the reported file name, fnix.exe, for immediate blocking and hunting rules.
• Utilized OSINT (Open-Source Intelligence) for initial triage, demonstrating the ability to quickly pivot and gather actionable data without executing the sample.

Ref 2: VirusTotal Details

• Confirmed Malicious Static Properties by reviewing the VirusTotal Details tab, noting the high detection score of 58/72.
• Extracted Key File Metadata including the file type, Win32 Executable (GUI), and compiler information (Microsoft Visual C/C++), which aids in attacker profiling.
• Verified Cryptographic Hashes (SHA256, MD5, SHA-1, Imphash) to ensure forensic integrity and provide multiple IOCs for internal detection systems.
• Extracted Core IOCs (Indicators of Compromise), including the MD5 and SHA hashes, and the reported file name, fnix.exe, for immediate blocking and hunting rules.
• Established Initial Timelines by documenting the Creation Time and First Seen In The Wild dates, providing crucial context for threat intelligence tracking.

Step 2. Reputation and Family Classification

Ref 3:VirusTotal Detection

• Established Threat Classification by noting the consensus Family labels of Zempack, Dridex, and IcedID (implied from the URL), which identifies the file as a dangerous banking trojan/loader component.
• Interpreted Sandbox Capabilities by reviewing the behavioral tags like direct-cpu-clock-access and detect-debug-environment, suggesting the malware employs anti-analysis techniques.
• Gathered Actionable Intelligence by extracting specific vendor detection names (e.g., Trojan.Win32.Zempack) for building targeted YARA rules and updating detection signatures.

Step 3. MITRE ATT&CK Mapping (Execution Vector)

Ref 4:MITRE ATT&CK T1204.002

• Mapped the Execution Chain to the MITRE ATT&CK framework, specifically identifying T1204.002, "User Execution: Malicious File."
• Contextualized the Attack Vector by documenting that the malware requires a user to manually open the file, defining the necessary Tactics, Techniques, and Procedures (TTP).
• Demonstrated Threat Intelligence Proficiency by linking the static analysis results of the executable to an industry-standard, actionable defensive framework.
• Defined Detection Requirements by confirming the initial security control failure involves Social Engineering and a failure in User Awareness that leads to execution.

Mitigation and Containment

• Isolate the Host: Immediately disconnect the infected endpoint from the network to prevent C2 communication and lateral movement.
• Block Hashes: Push the SHA256 hash and all other derived hashes to the EDR/Antivirus solution to globally block execution.
• Network Deny Rules: Deploy Firewall/Proxy Deny rules for any observed C2 IP addresses and domains (if available from dynamic analysis) to block external communication.
• Wipe & Reimage: Wipe the operating system and reimage the infected host to ensure complete removal of all persistence mechanisms (the safest option for confirmed loaders/trojans).
• Reset Credentials: Force a password reset for the compromised user across the domain, email, and any high-value accounts, as this is an information-stealing threat.
• Threat Hunt: Use the malware's known behaviors (T1547.001 Persistence) to search SIEM/EDR logs for similar activity on other hosts.
• Security Awareness: Update training with examples of the social engineering lure used to trigger the T1204.002 (User Execution) technique

Final Reflections

This project successfully affirmed the critical value of rapid, remote static triage in a SOC workflow, allowing us to immediately classify the file as a high-risk Dridex/Zempack loader using OSINT platforms. By quickly mapping the required user interaction to MITRE ATT&CK T1204.002, we defined a precise and actionable defensive strategy that focused equally on technical threat containment (hash blocking) and addressing the human vulnerability (user awareness). Ultimately, the exercise demonstrated the crucial ability to translate static file findings into a decisive containment and remediation plan, specifically by prioritizing host isolation and re-imaging to eliminate sophisticated persistence mechanisms.