Malicious PDF — malware analysis report

Static analysis result for SHA-256 202b9e738c26d457…

MALICIOUS

PDF

11.8 KB
MD5: 0cb4a12e0c8a649b04614134aac2bcab SHA-1: 4e8f6545f5d5c698a0e6b96b58ee5e82774f2bd1 SHA-256: 202b9e738c26d4578eda2baa0bedd38a339f1ea9cbf128c83b28c38757d19f9d
146 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF file contains embedded JavaScript that leverages the CVE-2007-5659 vulnerability, specifically targeting the Collab.collectEmailInfo function. The heuristics indicate that this JavaScript is responsible for decoding and executing further stages, likely downloading additional malicious content. The presence of deobfuscated JavaScript files named 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js' further supports this, suggesting a multi-stage attack. The exact nature of the second-stage payload is not detailed in the provided evidence, but the exploit chain is clear.

Heuristics 6

  • 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)
  • ClamAV: Pdf.Exploit.Agent-35903 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35903
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
860eae5f96eb426380281c575a089242b50523bbb4bbb8dd765e582cd9c07d2e
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 294 bytes
legacy_pdfkit_stage_000.js
bed67ffdade5763d10c5e537ace86ee799faf9ae6a8cebb50e97c07ad158de97
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x2E8 4941 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
2347d7797dc606de8caaa2701e141f201efe179d1d18dff42e56c827f14de5f9
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2E8 11880 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).