Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff9b2c3467079273…

MALICIOUS

PDF

20.6 KB Created: 2008-07-26 19:43:58 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: 26e1679c7fe4cd96dc6b40d38fc21348 SHA-1: 50614a758e07cdb9e9ad0b9b74174baed297a9e0 SHA-256: ff9b2c3467079273ceabb3c624d82a0e4c9269a4b985dcb3a66793c636002f6e
390 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 JavaScript is heavily obfuscated using quoted-hex fragments and appears to be a stager. ClamAV detections further confirm its malicious nature as a dropper. The primary attack vector is the exploitation of these CVEs to deliver a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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.Dropper.Agent-7329361-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7329361-0
  • 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.
  • Quoted-hex fragment JavaScript stager high PDF_QUOTED_HEX_FRAGMENT_JS_STAGER
    PDF JavaScript stores the hidden exploit stage as many quoted hexadecimal fragments, joins them through helper functions, and evals the recovered JavaScript. The decoder is bounded and only fires when the recovered stage contains concrete Acrobat exploit APIs or heap-spray shellcode markers.
  • 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_obj0013_000.js
f0de45ba117c2a441da86deb9aa3dd7eec8c275e3cb9235c8a035dd539641d4a
pdf-javascript-stream PDF /JS object 13 at offset 0x336 19542 bytes
javascript_obj0013_001.js
755737cee640525d333fb8d6a39fef1d73b1a3f1fb2815e1cf32440105d138c1
pdf-javascript-stream PDF /JS object 13 at offset 0x359 20247 bytes
quoted_hex_fragment_stage_000.js
1113561bfc0071dc2eefe4bb6e3d70224c8f9292347c8af2a5fe375d4694b89f
deobfuscated-js quoted-hex fragment decoded JavaScript object 13 at offset 0x41B 5705 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).