Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a4fb62fcd60eafe…

MALICIOUS

PDF

11.9 KB
MD5: 1f0237e3a430f6607e4439bf5fe3d3fc SHA-1: 62af808d8802bfce52bec1eda91abeadcbe470d8 SHA-256: 8a4fb62fcd60eafe1c0aac52a5fa8aceeff07a9a0c2a06586556fcd5e9ae60df
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, identified by multiple heuristics including PDF_JAVASCRIPT and PDF_JS. A critical heuristic, CVE_2007_5659, indicates the use of the 'collab.collectEmailInfo' method to exploit a known vulnerability, likely to stage and execute a secondary payload. The extracted JavaScript, particularly 'annotation_subject_callee_hex_stage_000.js', is heavily obfuscated but appears to be responsible for decoding and executing further malicious code, as suggested by the 'deobfuscated.js' artifact. The ClamAV detection further confirms the malicious nature of the file.

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
fb69294d6811f6a13624fc94b415dd2cc75d37b179562087d2ee7abbdd5e2750
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
3ee1ff3b63b29aff6ce67f352825063d2fdad937b3b2229ee83ffe26a1bb01f4
deobfuscated-js PDF JavaScript deobfuscation pass 78984 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).