Here are some statistics that you may find interesting. If you have any other suggestions for statistics that you'd like to see, feel free to contact us.
The following graph represents the volume of traffic attempting to send email to email addresses that do not exist.
There are many legitimate reasons an email could be sent to an invalid user, such as a typo being made in the email address. However, when it comes to high volumes this could be an indication of more a deliberate intent. For example:
Each column on this graph represents one week's worth of activity.
The following graph represents the number of unique sources attempting to perform authentication attacks (any form of password guessing attacks) by network.
Nowadays, we observe that major cloud services are being abused more and more frequently for use in authentication attacks. We are just as surprised as you may be when looking at the source of these authentication attacks. The trend towards utilizing these cloud services for malicious attacks is concerning.
These cloud services do not provide any transparency as to who or what is behind the attack, leaving the targets and victims vulnerable. Even if you block one offending IP, another IP from that network will come knocking on your server's door. This provides a haven where threat actors can hide behind a service and remain anonymous while performing password guessing attacks.