Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce355d25f99e8fe3…

MALICIOUS

PDF

11.8 KB
MD5: f713e54a50a39a3f18a2c871b077a65b SHA-1: b7e2cd53a8100ade7785d56d29db8e2eb136f3cd SHA-256: ce355d25f99e8fe35843ce031943c8b44f3dc60b03dd51062495fe718d81471b
146 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, identified as malicious by ClamAV (Pdf.Exploit.Agent-35903). Heuristics indicate the use of CVE-2007-5659, specifically targeting the 'Collab.collectEmailInfo' JavaScript function, to execute a staged payload. The embedded JavaScript streams, 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are likely responsible for downloading and executing further malicious content.

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
5f68b91b575a36dd27f6c78a1bfb43fcba10c7d4b573f643db1399855e11a329
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x2E8 4980 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
f9eda3ecd678e3b0f1766f9e409544dc607cdb6e92e624393b46be211d7fdd42
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2E8 12017 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).