Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cf9fb35df023a98…

MALICIOUS

PDF

12.1 KB
MD5: 2ee7316cb05e2f86ec9b7e10b8f45dd2 SHA-1: 168fe1782d274820e768d014c1695b0170cfab22 SHA-256: 4cf9fb35df023a98f0439fb75b899f18c8094fa9b1d9261aa39cb730c4a7d2b7
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF document contains embedded JavaScript that is obfuscated and staged. The critical heuristic CVE_2007_5659 indicates the exploitation of a known vulnerability in PDF viewers using the 'collab.collectEmailInfo' function. The JavaScript is further processed by a hex decoder before execution, suggesting it's a downloader or stager for a second-stage payload. The presence of multiple JavaScript files and the specific exploit technique point towards a malicious PDF designed to deliver further malware.

Heuristics 7

  • 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-36063 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36063
  • 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.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed 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
eb39e2de4dbbc100de6d3e30aa43ff78fa075618862ba1ebba5151ea3a3b848d
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 273 bytes
annotation_subject_callee_hex_stage_000.js
b9b4eea40d7427f2bf2a028c931425725888b09a3640a72c83bc6c04bdb4ec62
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5211 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
e0e1b2b584665bbf383307953a5b825fa2045bd0fe92aee19e43aa54c0473316
deobfuscated-js PDF JavaScript deobfuscation pass 73422 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).