HTTP flood attack tutorial - What is it and how does it work?

Explanation of HTTP flood

As the call implies, flood assaults “flood” a server with system-extensive requests till it now not has the ability to reply to valid consumer requests. While SYN or ACK flood assaults are accomplished at the community and shipping layer (Layers three and 4), HTTP or HTTPS flood assaults goal the utility layer (Layer 7) as a way to penetrate the weakest aspect of an infrastructure and for that reason purpose an overload. The special feature: in contrast to different assaults, HTTP floods are primarily based totally on technically efficiently formulated (legitimate) requests to the internet server being attacked. Because the malicious HTTP/S requests are definitely indistinguishable from everyday site visitors, they're especially hard to stumble on and protect in opposition to. However, with the proper safety era, this hassle also can be managed.

How an HTTP flood attack works

In an HTTP flood assault attackers flood an internet server with HTTP requests that particularly request pages with big loading volumes. This in the end reasons the server to overload and it's miles now not capable of system valid requests. As a result, the internet site or internet utility is now not handy for users.

Cybercriminals frequently rent botnets for such assaults to maximise the performance and effect in their assaults. Botnets normally encompass lots of commandeered after which remotely managed computer systems and networked structures from the IoT. They bombard the goal’s infrastructure with concurrent requests till it crashes below the load. The Myra SOC (Security Operations Center) has already determined HTTP flood assaults wherein the range of malicious requests rose to the mid-triple-digit million range.

Common varieties of HTTP flood assaults

The Hypertext Transfer Protocol (HTTP) offers numerous techniques for replacing information among an internet browser and a internet site. By a long way the maximum generally used are HTTP GET and HTTP POST. A GET request fetches records from the server with out converting any information on it. With the POST method, information is despatched to and processed at the server, which include content material from an internet form. HTTP flood assaults normally take benefit of those  HTTP techniques:

• HTTP GET flood:

In an HTTP GET flood assault, the attacker (through a botnet) accesses a huge range of pages on a internet site that include especially big static content material which include images. These documents then must be despatched every time via way of means of the internet server, which overloads it over time. As a result, it's miles now not capable of reply to valid requests, and the internet site or internet utility turns into inaccessible.

• HTTP POST flood:

In an HTTP POST flood assault, the attacker again and again sends information to the internet server as a way to boom the assets required at the server aspect to most ability with every request. As a result, the server will in the end be incapable of presenting any responses and the internet site or internet utility will now not be handy. Although this kind of assault is greater complex, it's also a great deal greater powerful than tremendously easy HTTP GET flood assaults. It reasons even greater harm with a in addition modest use of assets.

Methods for detecting HTTP flood attacks

Instead of infiltrating the gadget through protection vulnerabilities or injecting malware as in different assaults, in HTTP flood assaults criminals flood the server with legitimate requests. Since those are widespread URL requests, this site visitors is sort of indistinguishable from regular information site visitors. In addition, site visitors information which include the sender (IP address), client, or consumer agent identifier (browser call) may be manipulated and forged, which makes figuring out assaults even greater hard.

To reliably distinguish assault site visitors from valid consumer requests, it's miles critical to apprehend the content material of the requests and placed them in context. Modern safety structures try this via way of means of studying all incoming requests earlier than they attain the internet server. This permits them to robotically stumble on ordinary site visitors styles and keep off HTTP flood assaults at an early stage.

Methods to mitigate HTTP flooding attacks

Once the assault site visitors is identified, the requests related to it is able to be carefully blocked or discarded. This leaves the internet server with enough assets to reply to all valid requests. An extra verification system may be used to make sure that valid requests aren't inadvertently blocked or discarded: Requests categorised as illegitimate can regain their repute as valid requests via way of means of resolving a CAPTCHA. After being effectively verified, they're forwarded to the internet server and answered to.

In any event, protecting in opposition to HTTP flood assaults calls for know-how and era that best utility layer (Layer 7) DDoS safety can provide. Protection structures for the community and shipping layers (Layer three and 4), for example, are not able to differentiate among an HTTP GET flood assault and a legitimate download. Accordingly, reliably detecting assaults and safeguarding a internet site or internet utility calls for DDoS safety on all applicable layers. This is the best manner operators can save you assault-associated disruptions and downtimes, which might be frequently observed via way of means of lack of revenue, image, and trust.