PDF malware analysis — malicious · 4cd53f6460a106dc

MALICIOUS

PDF

118.6 KB

MD5: f2771a9e78f4b9bb06276d3c3b282c8e SHA-1: b252832d8eecabcad91491f89baa45c5667835da SHA-256: 4cd53f6460a106dc4dbc721dfcfd23d42c750918e619c6cac070fc8d2bf8c164

196 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 JavaScript/JScript T1204.002 Malicious File T1566.002 Spearphishing Attachment

The PDF file contains obfuscated JavaScript, including a large comment-padded eval stager and multiple calls to eval() and String.fromCharCode(). ClamAV detected this file as Pdf.Exploit.Agent-36086. The ML classifier also flagged it as malicious with a high probability. The presence of these indicators strongly suggests the PDF is designed to exploit a vulnerability and execute malicious code, likely a downloader for further stages.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 7

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.

Filename	Kind	Source	Size
`javascript_obj0006_000.js` `4f4481b195e998af7b84b8e5a206a8ccbe0ca8a7bf9c77b8eb20c0fed4f3104e`	pdf-javascript-stream	PDF /JS object 6 at offset 0x143	626554 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).
`legacy_pdfkit_stage_000.js` `81fda5ae62b1bdd2eedc009b746538de805cb6dbdcfa539c18ad25aad8302438`	deobfuscated-js	double percent-decoded annotation JavaScript at offset 0x143	262144 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 587 long base64-like blob(s).

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