Malicious PDF — malware analysis report

Static analysis result for SHA-256 4636cf67def48c62…

MALICIOUS

PDF

11.8 KB
MD5: 9303a4bd784b209a995b35cbc6a62180 SHA-1: 688fc2fdc2f6f9056c30a08bd5d22db2165c2c84 SHA-256: 4636cf67def48c62ebc216d19a9d9c53ddaedc044f23b7679299e46fffc3b81f
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.001 Malicious Link T1059.003 Windows Command Shell

The sample is a PDF file that leverages the CVE-2007-5659 vulnerability through the `collab.collectEmailInfo` JavaScript function. Embedded JavaScript, found in `annotation_subject_callee_hex_stage_000.js` and `deobfuscated.js`, is responsible for decoding and executing a secondary payload. This indicates a typical exploit delivery mechanism for PDF-based 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
0bd908385e6c1dd2b5d9db169d2b0c3968d218f30f80fb459e97c8c5362c7ac8
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5067 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
0dc1c089fd290965be02c3b0d7f7451087dddf33383c89da0788b32de9ad385d
deobfuscated-js PDF JavaScript deobfuscation pass 80750 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).