Malicious PDF — malware analysis report

Static analysis result for SHA-256 4891fc91db6dd93a…

MALICIOUS

PDF

12.3 KB
MD5: f25d90bdbbb79b750dd477dd23990797 SHA-1: 99193d0d0da1640d1e36c0425bf154cbffafecb1 SHA-256: 4891fc91db6dd93a3669236ce1be762429cf8536fc8ffd5595523c583051e264
180 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by the 'PDF_JAVASCRIPT' and 'PDF_JS' heuristics. The 'CVE_2007_5659' heuristic specifically indicates the exploitation of this vulnerability via the 'Collab.collectEmailInfo' method to execute a hex-decoded JavaScript stager. This stager is likely responsible for downloading and executing a secondary payload, a common technique for initial access and further system compromise. The 'ClamAV_DETECTION' heuristic 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-36165 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36165
  • Annotation subject callee-key hex JavaScript stager high PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER
    PDF JavaScript uses syncAnnotScan()/getAnnots() to read an indirect annotation /Subject stream, percent-decodes it through marker replacement, then uses a callee.toString()-derived key to decode and eval the final exploit stage.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
3f254d15363cfc46f758dc79a2cb1074c4072b68aa3f4c80a9bf6696d85176e0
pdf-javascript-stream PDF /JS object 7 at offset 0x1A6 1045 bytes
annotation_subject_callee_hex_stage_000.js
89588eace01e975b60c4a1c562549797887d6b44184c35cd0e447813e1f50679
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14F 5295 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).