Malicious PDF — malware analysis report

Static analysis result for SHA-256 15a365d7fc618ebc…

MALICIOUS

PDF

11.5 KB
MD5: 9eadf7865055e8af3c2aa8fb35d867f2 SHA-1: 75c0e3c979434d5a792d927ef7e14e2d6a4c4cba SHA-256: 15a365d7fc618ebc3101cfb5ea288af70deb2273714beaf164707dc0cba16054
318 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that exploits CVE-2007-5659, specifically targeting Adobe Reader versions affected by APSB08-13. The script is designed to download a second-stage executable from the URL http://directinmixem.com/nte/RFX1.exe/yH4d508a9cV03003f36002Rf1abe22610aT228b3ba8Q00000000900801F002d000aJ00000000l0007. The presence of shellcode download functionality and the critical heuristic firings strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 10

  • 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)
  • Adobe Reader APSB08-13 patch-range version gate (CVE-2007-5659) high CVE likely PDF_JS_ADOBE_APSB08_13_PATCH_GATE
    PDF JavaScript gates the exploit payload on (>= 8 && < 8.1.1) OR (< 7.1) — the Reader 7.0.x / 8.0–8.1.1 window patched by Adobe APSB08-13 for the CVE-2007-5659 Collab.collectEmailInfo buffer overflow. Only kits that target that exact bug check both of those patch points; benign scripts do not.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • ClamAV: Pdf.Exploit.Agent-36079 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36079
  • PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://directinmixem.com/nte/RFX1.exe/yH4d508a9cV03003f36002Rf1abe22610aT228b3ba8Q00000000900801F002d000aJ00000000l0007

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
ef8bdac794684ae9cd4eb7091d80e1c5ca478c06c639d72d01626c1f7ce78b6d
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 578 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
453b0d7622a23fa78458acdeb6eeee169dd53c4e372c20b49df9bcb52e6a45dd
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 11903 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
df84987c5ce8f249b68f9640511aff5bfc7976243aed3832b30230254f310eb3
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 4886 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).