Suspicious Double Extension Files
Last updated on:
In this page
About the rule
Rule Type
Standard
Rule Description
Detects dropped files with double extensions, which is often used by malware as a method to abuse the fact that Windows hide default extensions by default.
Severity
Trouble
Rule Requirement
Criteria
Action1: actionname = "File Created or Modified" AND ((FILENAME endswith ".exe,.iso,.rar,.svg,.zip" OR OBJECTNAME endswith ".exe,.iso,.rar,.svg,.zip") AND (FILENAME contains ".doc.,.docx.,.gif.,.jpeg.,.jpg.,.mp3.,.mp4.,.pdf.,.png.,.ppt.,.pptx.,.rtf.,.svg.,.txt.,.xls.,.xlsx." OR OBJECTNAME contains ".doc.,.docx.,.gif.,.jpeg.,.jpg.,.mp3.,.mp4.,.pdf.,.png.,.ppt.,.pptx.,.rtf.,.svg.,.txt.,.xls.,.xlsx.")) OR (FILENAME endswith ".rar.exe,.zip.exe" OR OBJECTNAME endswith ".rar.exe,.zip.exe") select Action1.HOSTNAME,Action1.MESSAGE,Action1.USERNAME,Action1.DOMAIN,Action1.OBJECTNAME,Action1.FILENAME,Action1.PROCESSNAME
Detection
Execution Mode
realtime
Log Sources
Windows
Author
Nasreddine Bencherchali (Nextron Systems), frack113
