DoS attack overloads the target host’s bandwidth: On a wide web of computers or devices that have already been infected with malware it can launch a coordinated multiplicity of online requests from the target host, which it cannot handle—hence crashes its functions and blacks them out to legitimate users. Because DoS attack uses only one
Distributed Denial-of-Service (DDoS) attack
Nevertheless, there is a form of DoS attack that is not easy to detect let alone remediate: Distributed Denial-of-Service (DDoS) attack. In this case, a cybercriminal infects computers with malicious software in order to gain control of them (that is turning them into zombie systems) and through this means sends spam and fake requests to the target. This barrage of bogus requests overload the target and overwhelm its functions, which causes it to black out to legitimate users. This type of attack is executed from multiple sources and detecting the IP addresses thereof can be extremely difficult—because as one is detected and blocked, other ones are coming in with their requests. This makes isolating legitimate traffic from fake ones almost impossible, thereby making it hard for a server to withstand a DDoS attack.
In this case, the victim computers are turned into zombie systems by infecting them with malware that is gotten across through a
An example of DDoS attack is the attack on
Moreover, as businesses and consumers communicate amongst one another more and more through digital platforms, DoS (and indeed DDoS) attacks will be on the rise. Even a company that has high-security protocols in place may be attacked through attacking a member in its supply chain if this member has inadequate security measures—because DoS attacks exploit any vulnerability in software and hardware to exhaust the
Motives of Denial-of-Service (DoS) attacks
DoS attacks on its own only shuts down a target—after which no data breach is experienced. However, it can facilitate other malicious activities, like stealing of:
- Financial data,
- Sensitive personal data,
- Email address and login credentials
- Intellectual property—like product design and trade secrets, and
- To gain access to an IT infrastructure.
Exploits that are mostly utilised in Denial-of-service (DoS) attacks
Methods of DoS attacks (in terms of the number of systems required in each case) have been elucidated upon hereinbefore, during which it was made clear that DoS attacks exploit the vulnerabilities in software and hardware to shut down a target. The following are examples of the exploits that DoS attacks utilise in their execution:
- Abuse of Transmission-Control-Protocol: In this case, a DoS attack sends numerous suspicious IP address(es) as requests to the target—while it is trying to grant these overwhelming requests, it stops attending to other legitimate users, hence the denial of service to legitimate users.
- Ping Flood: This is the abuse of the
Internet Control Messaging Protocol (ICMP) through echo requests—a situation in which a network administrator receives numerous specious network connections to it, and while trying to verify them, cannot verify the requests of legitimate connections. - Buffer Flood: In a computing system, instructions are held in the buffer, which oversees what memory space an application needs for its running. The buffer memory is limited in capacity and can only handle enough requests at a time. In a situation where it receives an overwhelming number of requests simultaneously, it will be unable to handle them and hence suspend other activities.