Malicious PDF — malware analysis report

Static analysis result for SHA-256 5707cfc1a6d731c9…

MALICIOUS

PDF

12.6 KB
MD5: 66f4c9786780d8e6d0e13f9e0f992533 SHA-1: 5851cb01c3b5bea5934d91574751ace4d7dc0faa SHA-256: 5707cfc1a6d731c960b3133bf0900cf18fe67368ef7240faec2d2535edb09ab2
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link or Unsafe File T1071.001 Web Protocols

The PDF file contains embedded JavaScript that leverages the 'collab.collectEmailInfo' function, known to be vulnerable to CVE-2007-5659. This JavaScript acts as a stager, deobfuscating and executing further JavaScript code from embedded streams. The deobfuscated scripts, identified as 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are responsible for downloading and executing a second-stage payload, indicated by the ClamAV detection 'Pdf.Exploit.Agent-36062'.

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-36062 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36062
  • 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
068944f8c011a88ab770b45c6de142b9305a1f515d410204d5eadd9ac2b5bfb3
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 373 bytes
legacy_pdfkit_stage_000.js
dc95734508b3864cc2b0ce75babee8ada5b2cf35c3f8416ea85a0d3de94bfcca
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2F5 12278 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
baf85c04ce80f8a36b74c0a42512d708b77646e8207ccda941a7dc8ac59eda39
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2F5 5070 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).