Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9d70d48fa59170e…

MALICIOUS

PDF

118.6 KB
MD5: 0b48e4452a3e3f746c67e4ff43014385 SHA-1: 80e2fa077a4ce9d0e61ad1ef80a8e9818c2d389a SHA-256: c9d70d48fa59170ea82e6eb10322f679818c284230a757ca5e4a2af54d805d4e
166 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which is a common technique for exploiting vulnerabilities. Heuristics indicate the use of eval() and fromCharCode, suggesting obfuscated code designed to execute. The 'Large comment-padded JavaScript eval stager' heuristic strongly suggests a payload delivery mechanism. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature, likely involving exploit code within the PDF.

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
05e7087e829d88f00151cba9bf13b1def015d00fae6ce3a6e699584f6f4e7a44
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627119 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).