Malicious PDF — malware analysis report

Static analysis result for SHA-256 f031bc59ef039a91…

MALICIOUS

PDF

11.4 KB
MD5: 8ecd18ec52ef39b9d536bb40118d4edc SHA-1: 8ab8f7015589f25a35a886bfa8a8ebcc7fddbae9 SHA-256: f031bc59ef039a918ff20e5a74d200dde5ae9fb746a97e9d580b27115c78bd1e
200 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript, identified by multiple critical heuristics including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER'. The 'CVE_2007_5659' heuristic indicates the use of a known vulnerability to execute JavaScript, which is further supported by the presence of deobfuscated JavaScript files ('legacy_pdfkit_stage_000.js', 'legacy_pdfkit_stage_001.js'). The primary function of the embedded scripts appears to be downloading and executing a second-stage payload, as suggested by the 'unknown_exploit_score' and the ClamAV detection '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
61966371f68495dc973db27a8c09c011947d3eb9423a5eb243f5a03df77efcfe
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x315 11631 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
7589cd705afaf0f9ee51c6b6058b27bed9c8ebd9cc686a7d173bfb3c7fbddabc
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x315 4794 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).