Automate E-mail Security Controls to Prevent Hacks through E-mail
E-mail is a common entry point for hack attacks on all kinds of systems – Windows, Linux, Unix – you name it. You can implement the following countermeasures as an additional layer of security for your e-mail systems:
Tarpitting: Tarpitting detects inbound messages destined for unknown users. If your e-mail server supports tarpitting, it can help prevent spam or DoS attacks against your server. If a predefined threshold is exceeded — say, more than ten messages — the tarpitting function effectively shuns traffic from the sending IP address for a period of time.
E-mail firewalls: E-mail firewalls and content-filtering applications from vendors such as Symantec and Barracuda Networks can go a long way towards preventing various e-mail attacks. These tools protect practically every aspect of an e-mail system.
Perimeter protection: Although not e-mail-specific, many firewall and IPS systems can detect various e-mail attacks and shut off the attacker in real time. This can come in handy during an attack.
CAPTCHA: Using CAPTCHA on web-based e-mail forms can help minimize the impact of automated attacks and lessen your chances of e-mail flooding and denial of service. These benefits come in handy when scanning your websites and applications.
Some e-mail servers, especially UNIX-based servers, can be programmed to deliver e-mails to a daemon or service for automated functions, such as create this order on the fly when a message from this person is received. If DoS protection isn’t built in to the system, a hacker can crash both the server and the application that receives these messages and potentially create e-commerce liabilities and losses.
This can happen more easily on e-commerce websites when CAPTCHA is not used on forms.