Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcc9c3f3b18d2121…

MALICIOUS

PDF

12.0 KB
MD5: 899e96176eecc29a131a5fd9dc42bd73 SHA-1: 35e9c50f1578a41b8968737f3f033dda6401a346 SHA-256: fcc9c3f3b18d2121c97415e3580bf5a8f0ded5470793faa789a39d2ae83cb0b0
186 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, identified by multiple heuristics including PDF_JAVASCRIPT and PDF_JS. The critical CVE_2007_5659 heuristic indicates the exploitation of a known vulnerability (Collab.collectEmailInfo) to execute a JavaScript stager. This stager is responsible for downloading and executing a second-stage payload, as evidenced by the large deobfuscated JavaScript file and the ClamAV detection of Pdf.Exploit.Agent-36063. The attack pattern is consistent with PDF-based malware delivery.

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
2e33a68fd404f8993af189fe2738f37cce8d665208295cb410c78ecc8cd0d336
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5084 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
35d8746eb8a9fca606fbdc91cf9a3b757689f75da7d5b50f9a1e656efd468aef
deobfuscated-js PDF JavaScript deobfuscation pass 78629 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).