Malicious PDF — malware analysis report

Static analysis result for SHA-256 e781bd06c4e98573…

MALICIOUS

PDF

11.9 KB
MD5: 326a13accd0abb6786eb2d2efcc5da14 SHA-1: ce411ac4c179e6f7b8e643b4379f5dc0e8184d5f SHA-256: e781bd06c4e98573627b094fcfdec5461ed0e70a8ae37d5aa9abee9795b88b7c
186 Risk Score

Malware Insights

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

The PDF file contains a critical heuristic firing for CVE-2007-5659, indicating the exploitation of a vulnerability related to the `collab.collectEmailInfo` JavaScript function. The analysis recovered a significant JavaScript stager (`annotation_subject_callee_hex_stage_000.js`) which was further deobfuscated into `deobfuscated.js`. This script is responsible for downloading and executing a second-stage payload, a common technique for initial access and further system compromise.

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
a3ee6c9c654253bf57bc1ba4ad2ad2842937931a9ff1c38289f855ba925f8e59
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5079 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
45af5fd77c66332fc33283238a01affd33b90bc2f473f2039601bca03f548a06
deobfuscated-js PDF JavaScript deobfuscation pass 78574 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).