PDF malware analysis — malicious · 5ef3e4c065035706

MALICIOUS

PDF

147.5 KB

MD5: c4031637b9ba93ed68ba7b9de2b943f8 SHA-1: 96f9e55d3c493578456f256900bb43b1b80aff7c SHA-256: 5ef3e4c065035706e2432b18309c84d573365e71661c4ab40a9c77d3a21dbdd2

238 Risk Score

Malware Insights

MITRE ATT&CK

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

This PDF file contains embedded JavaScript that is heavily obfuscated and utilizes a custom base64 decoding function. The JavaScript is triggered by an action within the PDF, and the critical heuristic firings indicate it's part of a known exploit cluster. The primary purpose of the script appears to be downloading and executing a second-stage payload from a remote location, as suggested by the obfuscated strings and the exploit cluster detection. The presence of the URL http://www.bitstream.com is noted, though its reputation is unknown.

Machine Learning

Nyx PDF Classifier malicious score 0.9998

Heuristics 9

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-36189 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Pdf.Exploit.Agent-36189
unescape() call high PDF_UNESCAPE

unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX

Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
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.
XFA form low PDF_XFA

PDF uses XML Forms Architecture — can contain script logic
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.
Embedded URL info EMBEDDED_URL

One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
URL http://www.bitstream.com
- http://ns.adobe.com/xdp/
- http://www.xfa.org/schema/xci/2.6/
- http://www.xfa.org/schema/xfa-template/2.6/

Extracted artifacts 3

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0013_000.js` `68e8076b6e64fcd2ca10303c831e0841eafa3d83ac1e82164314540de1873f22`	pdf-javascript-stream	PDF /JS object 13 at offset 0x10531	27749 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s).
`javascript_obj0013_001.js` `6e1501076275169d39f1993f04cd24aaf1fe0fd283583c60428c7b3dd756d228`	pdf-javascript-stream	PDF /JS object 13 at offset 0x1056D	27757 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s).
`font_00_sfnt_off00000352.bin` `a8f4d9b7d604c3c8a0bf3f9a31b9e952d467f98d118fdc784d95d689a14d8a33`	pdf-font-stream	PDF embedded font (sfnt) at offset 0x352	65932 bytes

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