Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f9e540f5011b53b…

MALICIOUS

PDF

15.7 KB
MD5: 3e608d4d7b671c3191f20a151bbe5b25 SHA-1: 8340cf0ae62c17f8dc80a924b8f7b740bc804b26 SHA-256: 4f9e540f5011b53b6ee0a7dd249ea4ff2b94b89f37eaf0e16cc1d520eb5147bf
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. A critical ClamAV detection ('Pdf.Exploit.Agent-36086') further confirms its malicious nature. The presence of a 'Large comment-padded JavaScript eval stager' suggests an attempt to obfuscate the execution of malicious code. The primary attack vector appears to be the exploitation of vulnerabilities within the PDF reader via the embedded JavaScript, likely leading to the download and execution of a secondary payload. No specific family could be identified.

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
0ea08be5f1f65ada12de08f78ec351f6946bba1d7fa7579db260cc30c685f377
pdf-javascript-stream PDF /JS object 6 at offset 0x143 424623 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).