alert tcp $EXTERNAL_NET any -> $HOME_NET [25,587] (msg:"ET EXPLOIT Possible CVE-2014-1761 Inbound SMTP 2"; flow:established,to_server; content:"xsaXN0b3ZlcnJpZGVjb3Vud"; isdataat:2,relative; pcre:"/^\s*/Rs"; content:!"DE"; within:2; content:!"DF"; within:2; content:!"Dk"; within:2; content:!"Dl"; within:2; content:!"DA"; within:2; content:!"DB"; within:2; content:!"DV"; within:2; reference:cve,2014-1761; reference:url,blogs.technet.com/b/srd/archive/2014/03/24/security-advisory-2953095-recommendation-to-stay-protected-and-for-detections.aspx; classtype:attempted-user; sid:2018308; rev:10; metadata:created_at 2014_03_25, deprecation_reason Age, confidence Low, signature_severity Major, tag CISA_KEV, updated_at 2024_03_06;)