Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b843472eac8c99f…

MALICIOUS

PDF

9.3 KB
MD5: 946660c75d2d1e25bf3612e87a0b12cf SHA-1: 7d26c1784cdafcf5f2eace152a700112563c9b95 SHA-256: 9b843472eac8c99f8908fc9647606922af97645e5b4e1f3f0ec479ece99ac96c
178 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which is a common delivery mechanism for exploits. Heuristics indicate the use of CVE-2007-5659, a known PDF vulnerability, and the ClamAV detection points to 'Pdf.Exploit.Agent-35905'. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are heavily obfuscated but suggest the execution of further malicious code, likely a downloader for a second-stage payload.

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-35905 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35905
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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.
  • 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
d8a6b4ad1abf04d0c4a4f89535cfb57f7312edef25c443f4e844c8ec9d0929dd
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 352 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
1f6ee0a970b2b899dba3db8e9fa81ea8a63daadd2b126d9792ae820e85b43bcf
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 12133 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
7d7ccf43d4348bb0ce1cfd7fa2ac6b7554472d3b1423924fa9a386b82ec11e3a
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 5100 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).