Malicious PDF — malware analysis report

Static analysis result for SHA-256 02db3909cadc15a8…

MALICIOUS

PDF

118.6 KB
MD5: 44eb8e1f55d66ce43fabca67a9029da1 SHA-1: 5bfa9e870a88b93df9659ebe2708b563321a2cc6 SHA-256: 02db3909cadc15a8e568d6a711b43aebee6579a6db2a8d059dce3b865aac1553
256 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution

The critical PDF heuristics indicate the presence of JavaScript exploits, specifically using eval() and String.fromCharCode, consistent with a stager designed to download and execute further malicious content. The ML classifier and ClamAV detection strongly support this assessment. The embedded JavaScript, though heavily obfuscated, is the primary mechanism for exploitation and payload delivery.

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
3b375e4d4aa4e66bec870c7fbbe00f999632e70fb6b072dd977aef51d3b52f1a
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627653 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_off0001d706.bin
ec4db4923ac1dc33fc2356dd2808dfcd1cf566ee74434a6a7c931b5bb70c3932
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1D706 300 bytes