Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9cef252be656f95…

MALICIOUS

PDF

7.4 KB Authoring application: Viraciregavi
MD5: 7cd9094e4d06779145dc542d2dc08baf SHA-1: a1d0dface3eab5bc850a9ae51b35a638360aa58a SHA-256: a9cef252be656f95ab46fd40cec0620faa96f0e82a611ff9cbfc78865f847b1d
368 Risk Score

Malware Insights

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

This PDF sample contains embedded JavaScript that utilizes eval() and unescape() functions, indicating obfuscation. Critical heuristics identify exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992, which are known PDF vulnerabilities. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, as suggested by the ML classifier and ClamAV detection. The document body text appears to be nonsensical filler, further supporting a malicious intent.

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.Exploit.Agent-35649 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35649
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
421ff05ad7aa306ab5a55fca23487fff3a3b0064e7a4c3e3f28138ca1123aecf
pdf-javascript-stream PDF /JS object 7 at offset 0x45A 5727 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
1e0c8ca4c6180400afd62497a161d41969b04e1091a2d4ffa9764c7f00cf51a1
deobfuscated-js string-concatenation normalized Acrobat API aliases at offset 0x45A 851 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 long base64-like blob(s).