Malicious PDF — malware analysis report

Static analysis result for SHA-256 ed965abdd973a554…

MALICIOUS

PDF

118.4 KB
MD5: 4b7b514299e9235c7efec8f39109764a SHA-1: 51ad2c49d431b3b4ec0672671dbfa5fb6cefcfb6 SHA-256: ed965abdd973a554d3276c33c6933c297de75ec134b05cd27ae08076894b8ac9
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information

The file is a PDF containing embedded JavaScript, as indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_JS_LARGE_COMMENT_PADDED_EVAL. The presence of eval() calls and String.fromCharCode suggests obfuscation and dynamic code execution. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly indicates malicious intent, likely involving the execution of a second-stage payload via the embedded script.

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
033a5afeef07208508b40ebeee6635d1e5a30bc3f194db7351abf442c9685b3e
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626140 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).