Malicious PDF — malware analysis report

Static analysis result for SHA-256 f61f296d353355db…

MALICIOUS

PDF

12.0 KB
MD5: b6e8d2773d18e4921496a781189d8f6e SHA-1: e1c8c64d12cb83a20db7b1fc02f7861b17baf14d SHA-256: f61f296d353355db6c3d910ce6acce64383dc87dd7d8c6d5fddd06f3fc8d4457
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is heavily obfuscated. Heuristics indicate the use of the CVE-2007-5659 vulnerability (Collab.collectEmailInfo) to execute this script. The script's purpose appears to be downloading and executing a second-stage payload, as suggested by the presence of multiple deobfuscated JavaScript files and the 'stager' naming convention. The high confidence is due to the critical heuristic firings and the clear indication of exploit usage.

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
4e7fd750e78d8233ad989b4029797103b85443c9246eba763c7d5df60f474454
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5111 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
73d8d819dc58886ec7e6b601f9eeb90c8ffacbf298068da1090146c5e70977c3
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2D6 12173 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
14aae3b7a43af2e9c3d748bd9fc767c71e890ac1829baef011355fa3be8464bc
deobfuscated-js PDF JavaScript deobfuscation pass 79401 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).