Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9f808985627f988…

MALICIOUS

PDF

12.3 KB
MD5: fa52d2f82686287d972dc353b0fdbd15 SHA-1: 6b5a3c811d080c6295d3f104f1b1dc9fbb006222 SHA-256: b9f808985627f98813514e22249d37d7e5327e831f1256ee0744ce517828058a
146 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by the PDF_JAVASCRIPT and PDF_JS heuristics. The critical CVE_2007_5659 heuristic indicates the use of a known exploit targeting Adobe Reader, specifically the Collab.collectEmailInfo function, to execute this JavaScript. The extracted JavaScript files, legacy_pdfkit_stage_000.js and legacy_pdfkit_stage_001.js, are likely responsible for downloading and executing a second-stage payload, as suggested by their size and the 'legacy_pdfkit_stage' naming convention. The ClamAV detection further confirms the malicious nature of the file.

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
700af6b23fdf19348df5a1d600cbded223e96213627b51bec8dc7e0cf6aafd5c
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x2E8 5226 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
9e7ed48efab7ea0587384f9efe8562ec29a6ff2a8cec3d11ae2f19d843af143d
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2E8 12442 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).