Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c4c2de54906d547…

MALICIOUS

PDF

15.7 KB
MD5: 577666dfe2be175811f86151b067ce32 SHA-1: c9eb56b41fecaacd0110bd009291a5388023e86d SHA-256: 9c4c2de54906d547732b9eea83ef43fc4de82cc58eab5f0204e9384921ecafa2
166 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which is a common technique for exploiting vulnerabilities and delivering malware. Heuristics indicate the use of eval() and String.fromCharCode, suggesting obfuscated code execution. The critical ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly suggests a known exploit. The embedded JavaScript stream, identified as 'javascript_obj0006_000.js', is likely responsible for the malicious activity, potentially downloading and executing a secondary 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
a767f3c40e4d0d886dff1ee7d00c13596d9e7fd7abdce969da30587beaa35b23
pdf-javascript-stream PDF /JS object 6 at offset 0x143 424697 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).