Malicious PDF — malware analysis report

Static analysis result for SHA-256 06a4efb2c765eebd…

MALICIOUS

PDF

118.6 KB
MD5: a0830e23188dba66f0ceed99679aaea5 SHA-1: a0962f1f3ee2fd13f19eab3777392aa5cc85d1f4 SHA-256: 06a4efb2c765eebd4a8b397f21d944629a94135c1af0a17b781bd128f3decdec
256 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

This PDF file contains obfuscated JavaScript that utilizes eval() and String.fromCharCode() functions, indicative of an exploit. The high ML score and ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly suggest malicious intent. The JavaScript is likely responsible for downloading and executing a secondary payload, a common technique for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
b2f1e40d1d252927495a9950513215b2ebc3731fe370bc5987059ff0fa2961b6
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627297 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).
stream_001_off0001d707.bin
f95af1b0b9586a86348f74e5fdafd178b3979d3ee77dd92843c540aeb33bbb29
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1D707 300 bytes