What is a Denial-of-Service Attack?
When authorised individuals are unable to gain access to information systems, gadgets, or other network resources owing to the acts of a hostile cyber threat actor, this is referred to as a denial-of-service (DoS) attack. Email, web pages, online accounts, and other services that rely on the afflicted machine or network may be disrupted. A denial-of-service condition is created by flooding the target’s network or host with traffic until the target is unable to reply or simply crashes, denying genuine users access. DoS attacks can cost a company both time and money since its services and assets are unavailable.
What are The Usual Denial-of-Service Attacks?
A DoS attack can be carried out in a variety of ways. The most frequent technique of attack involves flooding a network server with traffic. In this sort of DoS attack, the attacker makes several requests to the targeted server, causing it to become overloaded with traffic. These service requests are fraudulent, using forged return addresses that deceive the server when it attempts to verify the identity of the requestor. Because garbage requests are repeatedly processed, the server becomes overburdened, resulting in a DoS circumstance for legitimate requestors.
- The attacker uses a faked source Internet Protocol (IP) address which belongs to the target machine to transmit Internet Control Message Protocol broadcast packets to a list of hosts in a Smurf Attack. Those who receive these spoofed packets will then reply, flooding the targeted host with responses.
- A SYN flood happens when an attacker sends a connection request to the target server but fails to complete the connection via a three-way handshake—a technique used in a Transmission Control Protocol (TCP)/IP network to establish a connection between a local host/client and server. The incomplete handshake causes the connected port to be marked as occupied and unavailable for future requests. An attacker will keep sending requests, saturating all available ports, preventing legitimate users from connecting.
Individual networks may be impacted by DoS assaults even if they are not directly targeted. If the network’s internet service provider (ISP) or cloud service provider is targeted and attacked, the network will also go down.
So, What is a Distributed Denial-of-Service Attack?
When numerous machines work together to attack one target, it is called a distributed denial-of-service (DDoS) attack. DDoS attackers frequently utilise a botnet—a network of hijacked internet-connected devices—to launch large-scale attacks. Attackers use control and command software to control a large number of devices by exploiting security flaws or hardware weaknesses. Once in command, an attacker can direct their botnet to launch a DDoS assault on a target. The infected gadgets are also targets of the attack in this situation.
Botnets, which are composed of compromised devices, may also be rented to other possible attackers. The botnet is frequently made available to “attack-for-hire” services, which allow inexperienced people to initiate DDoS attacks.
DDoS enables significantly greater requests to be sent to the target, boosting attack power. It also makes attribution more difficult because the real cause of the attack is more difficult to determine.
DDoS assaults have become increasingly powerful as more gadgets connect to the Internet of Things (IoT). IoT devices frequently utilise default passwords and lack strong security postures, leaving them open to penetration and exploitation. Infection of IoT devices frequently goes unnoticed by users, and an attacker might quickly compromise hundreds of thousands of these devices in order to launch a large-scale attack without the device owners’ knowledge.
How Do You Protect Yourself From Being A Part of The Problem?
While there is no way to totally prevent being a target of a DoS or DDoS assault, administrators can take proactive efforts to mitigate the effects of an assault on their system.
- Enroll in a DoS protection service that identifies and redirects anomalous traffic flows away from your network. DoS traffic is screened out, and only clean traffic is routed through your network.
- Make a disaster recovery plan to enable efficient collaboration, mitigation, and recovery in the case of an attack.
It is also critical to take steps to increase the security posture of all internet-connected devices so as to keep them secure.
- Install and keep antivirus software up to date.
- Install and configure a firewall to limit traffic entering and exiting your computer.
- Assess security settings and adhere to proper security practises to limit who has access to your information and manage unwanted traffic.
How Can You Determine If An Attack is Happening?
A DoS attack’s symptoms may resemble non-malicious availability difficulties, such as technical issues with a specific network or a system admin performing maintenance. The following symptoms, however, may indicate a DoS or DDoS attack:
- Network performance that is unusually slow (opening files or visiting websites),
- Unavailability of a specific website, or
- Unable to get into any website at all.
The easiest technique for identifying and detecting a DoS attack is to monitor and analyse network traffic. A firewall or detection system for intrusions can be used to monitor network traffic. An administrator can also build rules that generate a warning when an abnormal traffic load is detected, determine the source of the traffic, and reject network packets that fulfill particular criteria.
What Steps Should You Take If You Suspect You’re Under Attack?
If you believe you or your company is the victim of a DoS or DDoS assault, you should immediately contact the proper technical experts for assistance.
- Reach out to your network admin to determine whether the interruption is due to maintenance or an internal network problem. Network managers may additionally track network traffic to validate the presence of an assault, determine the source, and mitigate the issue by implementing firewall rules or possibly redirecting traffic through a DoS mitigation service.
- Contact your ISP to see if there is a network outage or if their network is the intended target of the attack and if you happen to be an indirect victim. They might be able to guide you on the best course of action.
Do not lose track of the other hosts, resources, or services on your network in the event of an assault. Many attackers use DoS or DDoS attacks to divert attention away from their primary target and to launch secondary attacks on other services that are in your network.