Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a7af0309cc45048…

MALICIOUS

PDF

15.7 KB
MD5: 92c9060e70e55f6f96bd558e85575485 SHA-1: 17736e8ffd6c85c3fcb71d7a0ec06477f253288c SHA-256: 8a7af0309cc45048c56836f5cf44b696bb0e73875dae184ad18aaf70ceb1cd1f
166 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, as indicated by multiple PDF_JAVASCRIPT and PDF_JS heuristics. The presence of a high-severity PDF_EVAL and PDF_JS_LARGE_COMMENT_PADDED_EVAL firing suggests the JavaScript is designed to obfuscate and execute malicious code. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, a common technique for malware delivery.

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
41c6da5ec8ea341671a1d3c3c6459191b373aa13c568bc262e7f5137464d71b4
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425115 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).