Malicious PDF — malware analysis report

Static analysis result for SHA-256 f53589b0c5f9a469…

MALICIOUS

PDF

11.8 KB
MD5: 130183e46459077d9c50baf2ad48a40a SHA-1: fbbd9b81efc953f79449a8db56615d5eab94301b SHA-256: f53589b0c5f9a4694feae96ebfd70e47b639e22c115e2a730d79b387c9f783d5
146 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious Link/URL T1566.002 Spearphishing Attachment

The PDF file contains embedded JavaScript, identified by the PDF_JAVASCRIPT and PDF_JS heuristics. The critical CVE_2007_5659 heuristic indicates the use of the Collab.collectEmailInfo method, a known vulnerability exploited in older PDF readers. The embedded JavaScript is heavily obfuscated but appears to be designed to download and execute a second-stage payload. The ClamAV detection further confirms the malicious nature of the file.

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
a567b4e3561c26afc23ef0c6707bc0868d3486c1ee4106d33d83138a7478b3cb
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 12274 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
feb517b624c1bbad29cc4a3849853a69b7453168023eb322ed5e6cdcfac194b4
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 5042 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).