Malicious PDF — malware analysis report

Static analysis result for SHA-256 29961557f060d6a8…

MALICIOUS

PDF

43.5 KB
MD5: ae51743e1bde2806aadb6b8db3c8b333 SHA-1: f07f0d1c218fcd1310205f4e2eb06825134b029b SHA-256: 29961557f060d6a8b0b2b40111c1da314801882c0d9fddad1424510c78bbd479
106 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains obfuscated JavaScript, identified by the 'PDF_JS_OBFUSCATED_DROPPER' heuristic. This script is designed to act as a dropper, likely downloading and executing a second-stage payload. The presence of U3D content and the 'PDF_U3D_CVE_RELATED' heuristic suggest exploitation of a vulnerability related to Adobe Reader's 3D parsing capabilities. The extracted files 'deobfuscated.js', 'legacy_pdfkit_stage_000.js', and 'u3d_00_off000041b1.bin' are components of this malicious chain.

Heuristics 6

  • U3D/3D content in PDF — Adobe Reader 3D parser CVE-family indicator high CVE related PDF_U3D_CVE_RELATED
    PDF contains U3D (Universal 3D) or 3D annotation content — CVE-2011-2462 and CVE-2009-3953 are critical vulnerabilities in Adobe Reader's U3D processing that allow arbitrary code execution. U3D content in PDFs is extremely rare in normal documents.
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_dashed_payload, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
71f6881f7016ac071115207cf6f8d643d210cc9cf8198fe32f636ce385fec006
pdf-javascript-stream PDF /JS object 5 at offset 0x14F 766 bytes
legacy_pdfkit_stage_000.js
99c836e4f5d3742a9f7495341dc8c619422afd3261f9aa7c08aef0668089c333
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1C41 13088 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).
deobfuscated.js
4a3de2a8c798f13e3cd6a35c525b7bbb848be3ab4b6de9926fbb91759a4b0a32
deobfuscated-js PDF JavaScript deobfuscation pass 292451 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
u3d_00_off000041b1.bin
fb27c6f6ffe2b08a88f79f344ef3cb4f85460ac81a062194b6fd84ab6e48b628
pdf-3d-stream PDF U3D 3D stream at offset 0x41B1 28021 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.79, consistent with packed or encrypted content.