Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8ef1536bd0f4be0…

MALICIOUS

PDF

12.2 KB
MD5: 56f1c9e074e2f2735f298c9c2ac1a6b7 SHA-1: 3e79171d3fa35d69b4c0bf8d517ba569f14f6757 SHA-256: a8ef1536bd0f4be00c32b5dd76e335b0373ab2124f4514c7f569e5b7b2dd2c98
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious Link/URL T1071.001 Web Protocols

The sample is a PDF file that leverages the CVE-2007-5659 vulnerability through the `collab.collectEmailInfo` JavaScript function. The embedded JavaScript is heavily obfuscated but ultimately decodes and executes a secondary payload. This indicates a downloader or dropper functionality, aiming to fetch and run further malicious code. The presence of multiple JavaScript streams and the specific exploit technique strongly suggest malicious intent.

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
44f00d59221f08f246eb466bf2595673b734c4a5f20e69ff3260ff58fd3c4c02
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5199 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
3c3cd337fd89f4c43614fca81792aeef5b140370add361ce1e5c7d7cca06770c
deobfuscated-js PDF JavaScript deobfuscation pass 82024 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).