Malicious PDF — malware analysis report

Static analysis result for SHA-256 947fdcae3342efdb…

MALICIOUS

PDF

118.7 KB
MD5: 5cf92e2b13e177f51c7eab0787f376b4 SHA-1: 7c7085d14d09b57f358382600b775d2ca01fd585 SHA-256: 947fdcae3342efdbcff3c48a68618181b99ef43fbb9a8bf7baf128f5ad3f7e27
166 Risk Score

Malware Insights

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

The PDF file contains multiple heuristic firings indicating embedded and obfuscated JavaScript, including a high-confidence 'eval() call' and a 'Large comment-padded JavaScript eval stager'. 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 initial access and further infection.

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
8f1fb46a2a5d5238fc5bd4abf35536fcf5ec31bc98bd8ff4333a388e46a44374
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626407 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).