Self Extracting Package Creation Via Iexpress.EXE From Potentially Suspicious Location

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About the rule

Rule Type

Standard

Rule Description

Detects the use of iexpress.exe to create binaries via Self Extraction Directive (SED) files located in potentially suspicious locations. This behavior has been observed in-the-wild by different threat actors.

Severity

Trouble

Rule Requirement

Criteria

Action1: actionname = "Process started" AND (PROCESSNAME endswith "\iexpress.exe" OR ORIGINALFILENAME = "IEXPRESS.exe") AND COMMANDLINE contains " -n , /n , –n , —n , ―n " AND COMMANDLINE contains ":\ProgramData\,:\Temp\,:\Windows\System32\Tasks\,:\Windows\Tasks\,:\Windows\Temp\,\AppData\Local\Temp" select Action1.HOSTNAME,Action1.MESSAGE,Action1.COMMANDLINE,Action1.FILE_NAME,Action1.PROCESSNAME,Action1.USERNAME,Action1.PARENTPROCESSNAME

Detection

Execution Mode

realtime

Log Sources

Windows

Author

Joseliyo Sanchez, @Joseliyo_Jstnk, Nasreddine Bencherchali (Nextron Systems)