Malicious PDF — malware analysis report

Static analysis result for SHA-256 51149bfd4176d1b8…

MALICIOUS

PDF

11.6 KB
MD5: 4d16c584e8ecbb5d89e4933bf72ef8b0 SHA-1: 1e78788fa89b566a66247acfa1b1d0835a17ca2c SHA-256: 51149bfd4176d1b87142223d589275dd931f2ddb7fdc6c34b380fa195098ad02
186 Risk Score

Malware Insights

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

The sample is a PDF file that leverages the CVE-2007-5659 vulnerability (Collab.collectEmailInfo) to execute embedded JavaScript. The JavaScript is heavily obfuscated but appears to be a stager designed to download and execute a second-stage payload. The ClamAV detection ID 'Pdf.Exploit.Agent-36063' further confirms its malicious nature. The exact payload and ultimate goal are not discernible from the provided evidence.

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
2dbdb8bf1efefd098b91374a4bb85824436ba17bacdff704d85629527bd1fb8e
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 4901 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
7ba5cd232d29c2159338c366be35480e19c492b020cf1c19ce7a329bb9820db4
deobfuscated-js PDF JavaScript deobfuscation pass 75378 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).