Malicious PDF — malware analysis report

Static analysis result for SHA-256 2f1b2e300f3450c1…

MALICIOUS

PDF

15.8 KB
MD5: 8dc5ac6707c4fd8eb0eac97351644480 SHA-1: 2ceafbcf70fcdc63a924b29c5f128acb48111b16 SHA-256: 2f1b2e300f3450c14b24969aeb7c415b54fdf0a8ccd2a987022152bc5e8c0f92
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The 'Large comment-padded JavaScript eval stager' heuristic suggests a deliberate attempt to obfuscate the script's functionality. The ClamAV detection of 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The primary function of the embedded JavaScript appears to be the execution of a malicious payload, likely a downloader, as suggested by the eval() and fromCharCode() calls within the 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
35fc5b019af0e02eeed9ba0104432a9d9f450508d730b1990f1a06297f3669a3
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425190 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).