Malicious PDF — malware analysis report

Static analysis result for SHA-256 dce9813c9027bf41…

MALICIOUS

PDF

4.1 KB
MD5: 0f688a5533368dfc7d28dea50a57a61b SHA-1: 3abecf49d30b70d99332b8417450b641c83d75a0 SHA-256: dce9813c9027bf418e0acdaa12aa15869b963e012a9b0824131f907aaee51323
216 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1027 Obfuscated Files or Information

The PDF file contains embedded JavaScript that utilizes a custom Base64 decoder and `eval()` to execute obfuscated code. The critical heuristic `CVE_2008_2992` indicates the JavaScript is designed to exploit a vulnerability in Adobe Reader, likely to download and execute a second-stage payload. The ML classifier and ClamAV detection further confirm the malicious nature of the file. No specific family could be identified.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Dropper.Agent-7312858-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7312858-0
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (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.
  • 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_obj0013_001.js
2fdab1304495069bba614e60a2b40ffbe939bd6bde88aa57334d2acd51b1034f
pdf-javascript-stream PDF /JS object 13 at offset 0x368 6301 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
acroform_b64_00.js
c7d502c22a95aa65dd673285bb5df7f8280603044e260e5b165a9b967574dd23
deobfuscated-js PDF AcroForm base64 (decompressed) at offset 0x99D 3572 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s).
custom_b64_stage_000.js
85fe71200c33f398824631ccde606ec4fbbce8035fb8611c145accabab2137e1
deobfuscated-js custom Base64 decoded JavaScript layer 2 (PDF /JS object 13) at offset 0x95E 2025 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).