PDF malware analysis — malicious · 0838912eb1578fb0

MALICIOUS

PDF

15.0 KB

MD5: f2c789668f417ac5b93af39939ef7be1 SHA-1: 4a5d9b319aae89691c1d60bf6dd2ea0f78487c26 SHA-256: 0838912eb1578fb07f7c19b3aad226ed713a6b934eb23d65a36186108c485159

156 Risk Score

Malware Insights

MITRE ATT&CK

T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF file contains embedded JavaScript that is obfuscated and uses eval() and String.fromCharCode() to execute malicious code. This script is designed to download and execute a second-stage payload, as indicated by the PDF_JS_EXPLOIT_CLUSTER heuristic. The ML classifier also strongly suggests maliciousness. The exact nature of the second-stage payload and its ultimate destination could not be determined due to script truncation.

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. (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 3

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0004_000.js` `ba647ea2bda68f54ac2ef814f45456c00ef4be31b444e6bed32f204bbfe06a71`	pdf-javascript-stream	PDF /JS object 4 at offset 0xE1	312 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_000.js` `ca53d737bc9e13cbe9314e04d6d2f4aaf3125c32c0b74b4fc81b7c25ef6efe17`	deobfuscated-js	repeated-marker hex decoded JavaScript at offset 0x18FB	11827 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
`legacy_pdfkit_stage_001.js` `c122b9ef45b76224a58be2a6ff15a5ae74244eb96dc0c40310d50b58675628f7`	deobfuscated-js	nested inline base-23 callee-key decoded JavaScript at offset 0x18FB	4649 bytes

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