Using a blacklist to block malicious users and bots that would cause you aggravation and harm is one of the most common and oldest methods around (according to Wikipedia the first DNS based blacklist was introduced in 1997).
There are various types of blacklists available. Blacklists exist for IP addresses, domains, email addresses and user names. The majority of the time these lists will concentrate on identifying known spammers. Other lists will serve a more specific purpose, such as IP lists that help identify known proxies, TORs and VPNs or email lists of known honey pots or lists of disposable domains.
There are many different types of malicious activity that occur on the internet and there are various types of lists out there to help identify and prevent it; however, there are also various problems with lists.
The problem with Lists:
In order to first identify a malicious activity with a list, the malicious activity must first occur and then be reported and propagated. It is not uncommon for the malicious activity to stop by the time it has been reported and propagated. Not all malicious activities are reported. If you encounter the malicious activity before it is reported then you won’t be able to preemptively act on it.
IPs, Domains, Email Addresses and Usernames are dynamic and disposable. If a malicious user/bot gets blocked then they can easily switch to a different IP, domain etc.
Some lists offer warnings that blocking an IP address could affect thousands of users who depend on it in order to obtain crucial information that they would otherwise not have access to. So block responsibly.
Aggregating data to more effectively identify malicious activity:
Instead of looking at one list to perform a simple straightforward lookup, we can take advantage of multiple datasets to uncover patterns and relationships between seemingly disparate values. A simple example would be, relating user names to email addresses, email addresses to domains and domains to IP addresses, which allows us to view the activity of one value and compare it to behavior of other values. Using complex algorithms with machine learning to process large samples of data we can intelligently discern if a value is directly or indirectly related to a malicious activity.
How Service Objects keeps it simple for the user:
The DOTS IP Address Validation service currently has two flags to help its user deal with malicious IPs, ‘MaliciousIP’ and ‘PotentiallyMaliciousIP’. The ‘MaliciousIP’ flag indicates that the IP address recently displayed malicious activity and should be treated as such. The ‘PotentiallyMaliciousIP’’ flag indicates that the IP address recently displayed one or more strong relationships to a malicious activity and that it has a high likelihood of being malicious. Both flags should be treated as warnings with the ‘MalciousIP’ flag being scrutinized more severely.
The warning signs of online fraud are out there, but you need a means of discovering them. Our IP Validation service encompasses many of the identification strategies necessary to make split second decisions on would be attackers before any harm is done.