Malicious PDF — malware analysis report

Static analysis result for SHA-256 e79dd794803066ee…

MALICIOUS

PDF

2.2 KB
MD5: 8c4affb48217fd5aec0b1e1ebcb0c693 SHA-1: 1ab133019c1c0000ccf047cae8edd25fea90bad5 SHA-256: e79dd794803066ee07c7a3ec8c4042136527ea2f879ff1854caefc817abb5f18
166 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: Malicious File T1027 Obfuscated Files or Information

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_UNESCAPE. The JavaScript stream utilizes eval() and String.fromCharCode(), suggesting obfuscation to hide its true functionality. The ClamAV detection of 'Pdf.Exploit.Agent-36082' strongly suggests this is a known PDF exploit. The primary function appears to be the execution of obfuscated JavaScript, likely to download and execute a secondary payload, a common technique for initial access.

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 0x7E3 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
85338e3a3366d5853a247a8ed07244ea526c6ad24fe3788a9862499ae5170599
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).