Malicious PDF — malware analysis report

Static analysis result for SHA-256 27bebfb85acd29ef…

MALICIOUS

PDF

83.6 KB
MD5: a1a611ac8b0ca0b43c97d592155342c1 SHA-1: 0da03dbf610e50ab02dde5c9855ad609ee0c1e2f SHA-256: 27bebfb85acd29ef888edbb9ea672df7f520a99339e8f1d62123c274b4d9243e
418 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that leverages multiple CVEs related to Adobe Reader vulnerabilities, including media.newPlayer, Collab.getIcon, Collab.collectEmailInfo, and util.printf. The JavaScript is deobfuscated using a character table and appears to be a stager for further malicious activity, as indicated by ClamAV detections of Js.Exploit.HTML-29 on both the original PDF and an extracted JavaScript artifact. The primary attack vector is the exploitation of these known PDF reader flaws.

Heuristics 10

  • 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: Js.Exploit.HTML-29 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Js.Exploit.HTML-29
  • 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.
  • Character-table JavaScript eval stager high PDF_JS_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript reconstructs an exploit stage by indexing into a small character table, appending hundreds of one-character fragments, joining the array, and evaluating the result. This static fallback fires only after the bounded decoder recovers an exploit-like stage, so it catches this obfuscation even when no single CVE API signature is available.
  • 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_obj0076_000.js
d622e4f7ac19905a83991310f90d8cd7157add94218eaa8d0fe16aa61ca4e8e2
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 84662 bytes
Detection
ClamAV: Js.Exploit.HTML-29
Obfuscation or payload: unlikely
char_table_stage_000.js
f7d5a82c2167855c14c0edc6ba55375f9544f95c1cebbc5ac6d607262d7e5540
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x2FB 3852 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).