Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3dc49435fd4563b…

MALICIOUS

PDF

12.0 KB
MD5: 3f63d6811c03eb77db6199173e3dd887 SHA-1: c0bab3409ae130985569aff6f87e90cc70c16b6a SHA-256: c3dc49435fd4563b62c24fab84e303a981a2806845435cc000fbacaeecff9d48
200 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT' and 'PDF_JS'. Critical heuristics like 'PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER' and 'CVE_2007_5659' point to the exploitation of a known vulnerability (CVE-2007-5659) using a specific PDF function ('collab.collectEmailInfo') to execute a stager. This stager likely uses the extracted JavaScript files ('legacy_pdfkit_stage_000.js', 'legacy_pdfkit_stage_001.js') to download and execute a second-stage payload. ClamAV also detected this as 'Pdf.Exploit.Agent-36065'.

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)
  • Annotation subject percent-decoding eval stager critical PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER
    OpenAction JavaScript forces annotation enumeration, reads an annotation /Subject payload with getAnnots(), rewrites marker bytes into percent escapes, decodes it with unescape(), and dispatches it through eval. This is a high-confidence exploit-kit staging pattern. It is intentionally not mapped to CVE-2009-1492 unless getAnnots() itself carries the crafted integer or long argument shape for that vulnerability.
  • ClamAV: Pdf.Exploit.Agent-36065 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36065
  • 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.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser exited 1. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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
9c67560e8c63b720885d3efc1627b844b86a6ec08e99e5b65a22eae832045756
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 431 bytes
legacy_pdfkit_stage_000.js
09c0428a36660a118635716c2fe35feb5d2621c32ace96bb046d0e2dab224850
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x315 12383 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
3e51e2a4ba8092a0a3310e4c2fdd96fbca9100d58604577fbeddfb34674f2c37
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x315 5079 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).