Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e0395204d1abf82…

MALICIOUS

PDF

15.6 KB
MD5: 585df2f207cd4a8127f11a44879b1b91 SHA-1: 4a2864bad7eb2718eb136c5d00c80c7154492627 SHA-256: 8e0395204d1abf827e9fd78b7f8638861cac1ea4e21bc8157811dc3cfe69a149
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The PDF file contains embedded JavaScript that utilizes eval() and String.fromCharCode, indicating an attempt to obfuscate malicious code. The 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' heuristic firing strongly suggests a stager designed to download and execute a secondary payload. The ClamAV detection of 'Pdf.Exploit.Agent-36086' further confirms the malicious nature of the file, likely involving an exploit. No specific family could be identified, but the techniques point to a common PDF-based exploit delivery method.

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
5aaaed56aa6999062c3ced1465f9e34000b3b01d7bec334d7394cb37d32f1b28
pdf-javascript-stream PDF /JS object 6 at offset 0x143 423639 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).