Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b8955c901983571…

MALICIOUS

PDF

29.7 KB Created: "ðaÿ¿ä(——ÜÚÕ3¸¢»à¼óÕº, Authoring application: ˜5SmÎýÔu¦ÁîžæjŠã (via ˜5S~ÎýÔ¦ÄîŸæfŠô¢)
MD5: 780635b999df149956ee5e873e0070be SHA-1: 7e0251f2cc9703e25c3732bab2da6908cdd5218f SHA-256: 2b8955c901983571ed916056004fd3fd888a3c668a8dd18c07cdae09f3c51653
64 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information

This PDF file is encrypted and contains embedded JavaScript, a common technique to conceal malicious content. The JavaScript action, triggered by an optional content group, is likely responsible for decrypting and executing the hidden payload. The presence of a large JavaScript stream suggests it's used to download and execute a second-stage payload, making the overall intent a downloader. Confidence is moderate due to the obfuscation preventing a full analysis of the script's exact actions.

Heuristics 4

  • Encrypted PDF carries /JavaScript — payload hidden from static analysis high PDF_ENCRYPTED_WITH_JS
    PDF declares /Encrypt and also references an executable trigger (/JavaScript). Document encryption hides the JavaScript body and stream contents from static scanners — combined with auto-execution indicators this is a known evasion pattern used to deliver weaponised JavaScript that the analyst cannot inspect without the decryption key.
  • 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.
  • Optional Content Group with action trigger low PDF_OPTIONAL_CONTENT
    Optional Content Group (layer) co-occurs with an action trigger — content can be selectively hidden from viewers or scanners while the action still fires on open

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0009_000.js
3805acc170cdbd3240fa7c24c9aa41f0f30328b7269954000f9a75fda446fcb5
pdf-javascript-stream PDF /JS object 9 at offset 0x3CA 27854 bytes