Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1667ecbfa6456ad…

MALICIOUS

PDF

118.5 KB
MD5: 07eaa7810dddab1299a623e5552c652f SHA-1: 70c57b43f79a3fe26e99fef4f5301ba5218e118f SHA-256: e1667ecbfa6456ad7e91ac1bfe70e4d873264f10d385c7e8476fa4fe833d89c3
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript with multiple high-severity heuristic firings, including `PDF_EVAL` and `PDF_JS_LARGE_COMMENT_PADDED_EVAL`. These indicate the script is designed to be obfuscated and executed, likely to download and run a secondary payload. The ClamAV detection `Pdf.Exploit.Agent-36086` further confirms its malicious nature. No document body text was available for analysis, so the rationale is based solely on the script's behavior and the malware detection signature.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL
    PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
6ba3a2e402e0c1c6d036ba1f7a3b0e9dbdbe432f3d9ac5e8ff36cf8b3a58722c
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627333 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).