Malicious PDF — malware analysis report

Static analysis result for SHA-256 4eebe7d36c9ce2e4…

MALICIOUS

PDF

8.1 KB
MD5: 62543793caae92becba9f28df89c3843 SHA-1: 59be2b8138f53547de99621a81b0e2b9ce8a92eb SHA-256: 4eebe7d36c9ce2e4ad506875ad803ee4da04304fcd35360abacdfa071793621c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF document contains obfuscated JavaScript, identified as a dropper, that leverages the CVE-2007-5659 vulnerability. This script is designed to decode and execute a further stage payload, likely a downloader, from within the document's annotations. The presence of multiple deobfuscated JavaScript files and the critical heuristic firing for CVE-2007-5659 strongly indicate this attack vector.

Heuristics 7

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • 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.
  • 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)
  • 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
ab3f4be7a3e2e879e844dcace56ca59cf8fe7249dc5a05c90896f0c9e7dd732a
pdf-javascript-stream PDF /JS object 5 at offset 0x148 559 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
0423bb7629b4dbf82a982a5b5a75397bb5af996889dbe261fb7185aae324c161
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1AEF 1916 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
29f1434382e342987258885edbabd0a70c35a2f5f55a82edec722c333917c12e
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x374 4940 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
55e2a12e58aa89c3f3fb8acb3f58e17263560429e444c1d973226aa6d8157898
deobfuscated-js PDF JavaScript deobfuscation pass 45813 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).