The Cybersecurity and Infrastructure Security Agency (CISA) is aware of open-source reporting of targeted denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks against finance and business organizations worldwide. A DoS attack is accomplished by flooding the targeted host or network with traffic until the target cannot respond or simply crashes, preventing access for legitimate users. In a DDoS attack, the incoming traffic originates from many different sources, making it impossible to stop the attack by blocking a single source. These attacks can cost an organization both time and money while their resources and services are inaccessible.
If you think you or your business is experiencing a DoS or DDoS attack, it is important to contact the appropriate technical professionals for assistance.
- Contact your network administrator to confirm whether the service outage is due to maintenance or an in-house network issue. Network administrators can also monitor network traffic to confirm the presence of an attack, identify the source, and mitigate the situation by applying firewall rules and possibly rerouting traffic through a DoS protection service.
- Contact your internet service provider to ask if there is an outage on their end or if their network is the target of an attack and you are an indirect victim. They may be able to advise you on an appropriate course of action.
For more information, see CISA’s Tip on Understanding Denial-of-Service Attacks.