Malicious PDF — malware analysis report

Static analysis result for SHA-256 20fb0cf8eea4972b…

MALICIOUS

PDF

13.4 KB Authoring application: Toldihiqanopo
MD5: 787d09cd80f71dd037641611af99e3a9 SHA-1: 8e96978e8f96db994a3b4bc563443679bc07b4fa SHA-256: 20fb0cf8eea4972b8c701c604355c5babb3ac82af6f75ef84443cc42453042e8
378 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

This PDF file contains multiple critical heuristic firings indicating exploitation of known PDF vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992). These vulnerabilities are used to execute XOR-decoded JavaScript. The deobfuscated JavaScript, found in page_word_xor_stage_000.js, is likely responsible for downloading and executing a second-stage payload. ClamAV also detected the file as Pdf.Exploit.Agent-36176.

Heuristics 9

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • 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-36176 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36176
  • 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.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0020_000.js
681fb8346e2ca0f375d9beeba24e43a3b31939102901566b68fd3c4bfab16eb4
pdf-javascript-stream PDF /JS object 20 at offset 0x29CB 284103 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36176
Obfuscation or payload: unlikely
page_word_xor_stage_000.js
f79cb6396492fc3f84d20f988f26cb4025557f9420c0051b290e67aa8c54f506
deobfuscated-js page-word XOR decoded JavaScript (decompressed, key=0x05) at offset 0x9E6 3215 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).