PDF malware analysis — malicious · 63e2b796619a799b

MALICIOUS

PDF

4.4 KB

MD5: 4d1d7da2afa466ddc20cc149a5e00f5c SHA-1: 39379db65782aa7f5f234097aea32b4b34219f54 SHA-256: 63e2b796619a799b316a2b5b3d16ca9e547a521b83bcb80b05202dd46a15c062

116 Risk Score

Malware Insights

MITRE ATT&CK

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

The PDF contains embedded and obfuscated JavaScript, identified by heuristics like PDF_JAVASCRIPT and PDF_JS_EXPLOIT_CLUSTER. The JavaScript is designed to download and execute a second-stage payload, as indicated by the use of String.fromCharCode and the ML classifier's high confidence in maliciousness. The primary IOC is the embedded JavaScript file itself.

Machine Learning

Nyx PDF Classifier malicious score 0.9999

Heuristics 5

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.
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.

Filename	Kind	Source	Size
`javascript_obj0002_000.js` `5383783eb4455ba0493b574453631313d3e594d562d061be97adb62e1dbffc2a`	pdf-javascript-stream	PDF /JS object 2 at offset 0x7B	105947 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 eval/decoder/string-building token(s).

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