Malicious PDF — malware analysis report

Static analysis result for SHA-256 5beb65653bb95e69…

MALICIOUS

PDF

5.9 KB
MD5: 2941189427322af3a5d8451cd4cebc49 SHA-1: 58d0fdc19fae8d2d2068c5b0d0056ed35fe6f534 SHA-256: 5beb65653bb95e69dbcf97b8c4ce3d895a2c505221fd2e463c3706673fdc6a75
308 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 utilizes the unescape() function and a printf() call associated with CVE-2008-2992. The JavaScript is heavily obfuscated but appears to be a dropper mechanism, as indicated by the 'generic_stage_recovery' heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to download and execute a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 8

  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (matched in decompressed stream)
  • 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.Dropper.Agent-7263825-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7263825-0
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • 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.
  • 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.

FilenameKindSourceSize
javascript_obj0006_000.js
67daa864f362d775f7d47cbc2de5c4fd4a7e54976ab96531fe3849103114e169
pdf-javascript-stream PDF /JS object 6 at offset 0x193 5170 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
generic_stage_recovery_000.js
7aa1a7a622dc7de1c2bdedf8daeee484b79622e48f5a1db6b1129bd73b54de3a
deobfuscated-js generic stage recovery percent-decode from JavaScript object 6 at offset 0x193 5168 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).