Malicious PDF — malware analysis report

Static analysis result for SHA-256 3889fd1e6ce0a69e…

MALICIOUS

PDF

12.2 KB
MD5: 24c12a92f85f878b100306c9c7cff31c SHA-1: d760006942313a7270f003de275451fc45334f50 SHA-256: 3889fd1e6ce0a69e4b90fb68160a99b235b40312fa18380b8901b894775326f3
188 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The critical CVE_2007_5659 heuristic specifically points to the use of the Collab.collectEmailInfo method to stage and execute JavaScript. This JavaScript is likely responsible for downloading and executing a second-stage payload, as suggested by the large size of the deobfuscated JavaScript files and the ClamAV detection of Pdf.Exploit.Agent-36063. The attack pattern involves exploiting a known PDF vulnerability to achieve arbitrary code execution.

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 4

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
05678d94dc07131c6958067ddbd0acf239661ac01ad62213ae7b4ce598183e25
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5194 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
3b935b45e269dc81ce3aa9810fa3a64839c74c3467f2c43cfb7604b4a5c58c11
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12409 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
046a3cf1f183fc152fa22c31d3cf0bb6c91dd9310c625274b3ac172e015f7d57
deobfuscated-js PDF JavaScript deobfuscation pass 79743 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).