Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3f6aaa7435c54d8…

MALICIOUS

PDF

5.9 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe (via Notepad)
MD5: 6d558a0a34d13520cc228ba6bd119df8 SHA-1: e4370f1d17fc8a76cd29e2d6d8d5e69f308671ce SHA-256: b3f6aaa7435c54d823980777ec8398624598a2f94b7aa6b58a616c849ec026a4
358 Risk Score

Malware Insights

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

This PDF file contains multiple critical heuristic firings indicating exploitation of known Adobe Reader vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992). These exploits are designed to execute embedded JavaScript. The extracted JavaScript streams, particularly 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are heavily obfuscated but indicate the execution of shellcode, consistent with a multi-stage exploit kit. The primary intent appears to be the download and execution of a second-stage payload.

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
d599c7c85da648911b325b0b58a3f3800c29fda9cf4e5afb7f28fb61a06cef60
pdf-javascript-stream PDF /JS object 6 at offset 0x1389 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
de76bf0c98f014e6f9a0ddf3ad28f67107d8f5011691e977956f92335982a43c
deobfuscated-js metadata placeholder percent-decoded JavaScript at offset 0x16E 4971 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
87b3a94efca9ed977565c73ab8053429f6731043a18c9bebffa26862dc9fcbae
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x16E 4967 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).