PDF malware analysis — malicious · 5a62c95b18682d8d

MALICIOUS

PDF

36.3 KB Created: 2010-02-08 21:57:48 Authoring application: PyZmYWRDoKkIMkLECj (via FkpsNSREPOkapNLtnTC)

MD5: 8482d097d0538fece134a95d6fb5e1fc SHA-1: 520bdf6a3ab84673cc651594684793086d648fd9 SHA-256: 5a62c95b18682d8dfdffe7b109af2fe3a75d820e913653e91dfe5f1bb0e94dfa

156 Risk Score

Malware Insights

MITRE ATT&CK

T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF sample contains embedded JavaScript that utilizes `eval()` and `String.fromCharCode()` functions, indicating an attempt to obfuscate malicious code. The ML classifier and heuristics strongly suggest this is a malicious PDF exploiting a known cluster of JavaScript vulnerabilities. The embedded JavaScript is likely responsible for downloading and executing a secondary payload, a common technique for malware delivery.

Machine Learning

Nyx PDF Classifier malicious score 0.9999

Heuristics 6

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.
eval() call high PDF_EVAL

eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
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.
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.

Filename	Kind	Source	Size
`javascript_obj0021_000.js` `c732736721dc844d73bc27979ac49a3cd3d6cbf374c6ac6323cdfb7d58b35e8e`	pdf-javascript-stream	PDF /JS object 21 at offset 0x4EEF	15845 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 12 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).

Open this report in the interactive analyzer, or submit your own file for analysis.