Malicious PDF — malware analysis report

Static analysis result for SHA-256 b57adbcf15334459…

MALICIOUS

PDF

11.9 KB
MD5: b87ad50d25b999e6a561ea451a987c55 SHA-1: 23d41fac8512f5f136f4ad8ad60c7dc18b396a23 SHA-256: b57adbcf153344595e7890f976589c9fc0d6170ce71f0829959a9b5c088bbded
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is triggered by the CVE-2007-5659 vulnerability, specifically targeting the Collab.collectEmailInfo function. This JavaScript acts as a stager, deobfuscating and executing further code. The presence of multiple deobfuscated JavaScript files and the ClamAV detection of 'Pdf.Exploit.Agent-36063' strongly indicate a malicious exploit delivery mechanism. The primary attack vector is the exploitation of a known PDF vulnerability to download and execute a secondary payload.

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 4

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
e3a449e727a6a65408b96868855b028ea0122f6b1d73d14aa78167089760b591
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5112 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
ee38412ffdb84efd4ae8679304a276a2e71a00fb1ce937be2876655a99645ca2
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12239 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
3525099e0fe15798f175f8b68fa3e11185b5bbefb6f8fb8f96d5fa7055c0bba8
deobfuscated-js PDF JavaScript deobfuscation pass 71739 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).