Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce41ee53f7460f72…

MALICIOUS

PDF

11.9 KB
MD5: ddab36eaf9d9ba47fcf47e257ff0ddf1 SHA-1: df123f0d0be1b7c5be75b01c89a9983c4b3a6b85 SHA-256: ce41ee53f7460f7299ccb25bbd93ea4ef06a446422f12d34171de640c59c63e4
146 Risk Score

Malware Insights

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

The critical heuristic CVE_2007_5659 indicates the exploitation of a known PDF vulnerability using JavaScript. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are heavily obfuscated but suggest the execution of malicious code. The ClamAV detection further supports the malicious nature of the file. The primary attack vector appears to be leveraging the 'Collab.collectEmailInfo' method to execute arbitrary JavaScript, which is then used to download and execute additional stages.

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-36079 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36079
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded 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
ef8bdac794684ae9cd4eb7091d80e1c5ca478c06c639d72d01626c1f7ce78b6d
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 578 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
73a6d115eae393717e19d185cc1fd89e114050c7101737a37014d0d84fe1e621
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 12495 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
ae8f1a6e5862c34dd417427bba7b8c3882bf09c3a0957d88ee4e0bf802df606b
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 5091 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).