Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a25fcba3b6cb4f8…

MALICIOUS

PDF

11.8 KB
MD5: ae5b4ddfeb279b32f3f3dc0a67f2f5db SHA-1: 5a7d5959dafa5f1f08d00aa72efd149e99219fcc SHA-256: 9a25fcba3b6cb4f81ae220593d3dc778e5092c61a0b62710a911e395cf7e97cf
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. Static analysis recovered two deobfuscated JavaScript files, legacy_pdfkit_stage_000.js and legacy_pdfkit_stage_001.js, indicating a multi-stage attack. The presence of these scripts and the critical heuristic firings strongly suggest the file's purpose is to exploit this known vulnerability to download and execute 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
cd218bb04f8fdf3dcc906ce2ff92236bbc9c30a8f8afb68a6ba3123e97078b15
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x2E8 4995 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
ac64bf98c8e2b1230a9b821d26f48bc4b874748d50faabd9904c713e82884ebd
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2E8 11991 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).