Malicious PDF — malware analysis report

Static analysis result for SHA-256 d44d8c202ced7c5f…

MALICIOUS

PDF

118.5 KB
MD5: 3fe58d9f946c17f7b4ad891bc32c8080 SHA-1: 0d83edd71c75790f8e48bf0d565ab7743c74fede SHA-256: d44d8c202ced7c5f352ebf65abe1afb77d67586b118f0f511d5b11aa3c87f02b
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript

The PDF contains embedded JavaScript, with heuristics indicating the use of eval() and String.fromCharCode, suggesting code obfuscation and execution. The 'Large comment-padded JavaScript eval stager' heuristic and ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly indicate malicious intent. The primary function appears to be the execution of obfuscated JavaScript, likely to download and execute a second-stage payload.

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
3d7c9bf1e247fa11a18ffd0b5c3b47907f92ab58bd06e3198d93903e300f248b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626679 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).