Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6f2102bcbbe2a80…

MALICIOUS

PDF

102.4 KB
MD5: a636a488d9b5cea29a05cfd75efa3791 SHA-1: 0b0a5a145f7c7dc5f57f91a999b641d44ff77656 SHA-256: a6f2102bcbbe2a80e9993dc2dbf3683ca5401234c001d9f82a93634b5daa6f66
418 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1027 Obfuscated Files or Information

The PDF file contains obfuscated JavaScript that leverages multiple CVEs related to PDF vulnerabilities to execute malicious code. The JavaScript is deobfuscated using a character table, indicating a stager designed to download and execute a second-stage payload. The presence of ClamAV detections for Pdf.Trojan.Agent-36936 and Js.Exploit.HTML-29 further supports its malicious nature.

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: Pdf.Trojan.Agent-36936 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Trojan.Agent-36936
  • 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
4bdff93504923b022ab2a2364ed38128020a05ce83dcc970f5b6239bae9e3c5d
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 96221 bytes
Detection
ClamAV: Js.Exploit.HTML-29
Obfuscation or payload: unlikely
char_table_stage_000.js
666fffae0fe9dbe1d381ade9973f3afe305a2e3d68837c36a4668df1ee699129
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x2FB 3864 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).