Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b28f16d4f2b3bf8…

MALICIOUS

PDF

2.2 KB
MD5: 7d34611a89ecd55bc6a8e72a7cc555e0 SHA-1: 04459ca5a082a4ac6c9c422565f101f87d42afe3 SHA-256: 7b28f16d4f2b3bf878c7d996a7487b38bdb310ec700f9caed8239cadb62b8be4
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell T1204.002 Malicious File: Malicious File

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript stream utilizes eval(), unescape(), and String.fromCharCode(), suggesting obfuscation and dynamic code execution. The ClamAV detection 'Pdf.Exploit.Agent-36082' further confirms its malicious nature. The primary attack pattern involves exploiting PDF vulnerabilities to run this script, which is designed to download and execute a secondary payload.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36082 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36082
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111611_000.js
772da696bdb365f3f1eb4ea6af881baad391be62f3591b19f2f9827fcc4c9b53
pdf-javascript-stream PDF /JS object 111611 at offset 0x7D9 479 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
b6f13b11e68e885830572c65ebe79f01e922f6b25c024628d01c6ddb7af675c4
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2828 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).