Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf9c0d0b0e3f009c…

MALICIOUS

PDF

9.3 KB
MD5: f10c4552893c05cdb440ffe7d6e9699b SHA-1: f87ebb265f6666dec92462dd5ba817bbf6bcca33 SHA-256: bf9c0d0b0e3f009c53cdd9b5de0e29f957bf0cb2718c0abb8312c69349ad9f62
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious Link/URL

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 vulnerability in PDF readers related to the Collab.collectEmailInfo method. The embedded JavaScript is heavily obfuscated but the presence of unescape() calls and the ClamAV detection signature 'Pdf.Exploit.Agent-35905' strongly suggest malicious intent, likely to download and execute a secondary 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
4fcab22a2db08ce220c55f66f5277e8975bbc356413ad18dda56a24b44730fe6
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 11916 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
683cb4903c9d6313bc00b7d004d045939c949de1dc22a7aadc966472f13e9d22
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 4955 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).