Snort email rules and regulations

Here are some common email rules and regulations that can be implemented using Snort:

1. Block Spam

• Rule: alert tcp any any -> any any (msg:"Spam email"; content:"X-Spam-Flag"; depth:10; classtype:trojan-activity; sid:1000001; rev:1;)
• Description: This rule blocks emails that have a specific header indicating they are spam.

2. Block Phishing Emails

• Rule: alert tcp any any -> any any (msg:"Phishing email"; content:"Subject: Your account has been compromised"; depth:20; classtype:trojan-activity; sid:1000002; rev:1;)
• Description: This rule blocks emails with a specific subject line that is commonly used in phishing attacks.

3. Block Malware Attachments

• Rule: alert tcp any any -> any any (msg:"Malware attachment"; content:".exe"; depth:10; classtype:trojan-activity; sid:1000003; rev:1;)
• Description: This rule blocks emails with attachments that have a specific file extension (in this case, .exe) that is commonly used by malware.

4. Block Emails from Known Spam Sources

• Rule: alert tcp any any -> any any (msg:"Spam from known source"; content:"@spamhaus.com"; depth:10; classtype:trojan-activity; sid:1000004; rev:1;)
• Description: This rule blocks emails that come from a specific domain (in this case, @spamhaus.com) that is known to be a spam source.

5. Block Emails with Suspicious URLs

• Rule: alert tcp any any -> any any (msg:"Suspicious URL"; content:"http://example.com/evil"; depth:20; classtype:trojan-activity; sid:1000005; rev:1;)
• Description: This rule blocks emails that contain URLs that are known to be malicious.

6. Block Emails with Specific Keywords

• Rule: alert tcp any any -> any any (msg:"Email with specific keyword"; content:"password reset"; depth:10; classtype:trojan-activity; sid:1000006; rev:1;)
• Description: This rule blocks emails that contain specific keywords (in this case, "password reset") that are commonly used in phishing attacks.

7. Block Emails from Unknown Senders

• Rule: alert tcp any any -> any any (msg:"Email from unknown sender"; content:""; depth:10; classtype:trojan-activity; sid:1000007; rev:1;)
• Description: This rule blocks emails that do not have a valid sender address.

8. Block Emails with Large Attachments

• Rule: alert tcp any any -> any any (msg:"Large attachment"; content:".zip"; depth:10; classtype:trojan-activity; sid:1000008; rev:1;)
• Description: This rule blocks emails with attachments that are larger than a certain size (in this case, a .zip file).

These are just a few examples of email rules and regulations that can be implemented using Snort. The specific rules and regulations will depend on the organization's email security policies and the types of threats they are trying to mitigate.