Malicious PDF — malware analysis report

Static analysis result for SHA-256 38c2f44acca7b232…

MALICIOUS

PDF

5.8 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe (via Notepad)
MD5: 2e90c10171317f2d2a9ccc0e2a02ec80 SHA-1: 92c9cecd3f8a067ac4bd6ad0a72e5e07e75202d7 SHA-256: 38c2f44acca7b2328d96a1e894250dbb9fe5f5aae04516c48c74cb250d2772ba
358 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of known Adobe Reader vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) via embedded JavaScript. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are deobfuscated and likely responsible for downloading and executing a secondary payload, as indicated by ClamAV detections on extracted artifacts. The presence of 'eval()' calls further supports the dynamic execution of malicious code.

Heuristics 9

  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • 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)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-35931 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35931
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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.
  • 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_obj0006_000.js
05d01ab9fe2bc6d464d6725b5e924af7c7b860d6ed200b37d8f363c860029228
pdf-javascript-stream PDF /JS object 6 at offset 0x136C 906 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
2f042f6cfe18675ae49762ad8d9778a4ee30c6f46968ae8a31247fcdd37e5deb
deobfuscated-js metadata placeholder percent-decoded JavaScript at offset 0x16E 4917 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
9fe886ff6f302690915e60c68a081f235768f9ff3f60b94d3198287646b54afa
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x16E 4913 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).