Rule History

SID: 2032345 • Source: et/open

Versions (4)

Version DetailsCurrent

Rev: 1 • Mar 29, 2021, 12:00 PM

Message:

ET WEB_CLIENT Exchange Webshell CnC Domain in DNS Lookup

Rule:

alert dns $HOME_NET any -> any any (msg:"ET WEB_CLIENT Exchange Webshell CnC Domain in DNS Lookup"; dns.query; content:"brian.krebsonsecurity.top"; nocase; bsize:25; reference:url,krebsonsecurity.com/2021/03/no-i-did-not-hack-your-ms-exchange-server/; classtype:domain-c2; sid:2032345; rev:1; metadata:created_at 2021_03_29, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_03_29;)

Created:

Mar 29, 2021, 12:00 PM

Updated:

Mar 29, 2021, 12:00 PM

DB Created:

Sep 21, 2024, 3:00 AM

DB Updated:

Sep 15, 2025, 9:36 PM

Filename:

rules/emerging-web_client.rules