Category Archives: Servers

DKIM record – Everything you need to know

DKIM record – What does it mean?

The DKIM record, or DomainKeys Identified Mail, is a security standard allowing domains to sign outgoing emails through cryptographic authentication. In this approach, domains can demonstrate that the emails arriving from their end are authentic. So they are trustworthy. The DKIM record also protects communications to stop tampering with them while in transit (sending server-recipient server).

How does it function?

In addition to collaborating with SPF and DMARC to create several layers of security for domains sending emails, DKIM is compatible with the current email infrastructure. When an email leaves the sender server, it is signed with a private key using public-key cryptography.

Then, in order to confirm the message’s origin and ensure that it was not altered in transit, recipient servers employ a public key that has been made available to a domain’s DNS. Finally, the email passes DKIM and is valid if the receiver server confirms the signature using the public key.

How to check DKIM record?

Advantages of utilizing DKIM record

  • DKIM is easily enabled. It is a self-certification mechanism. Therefore, three-party certification is not necessary for it to function.
  • It protects your users from forged emails. The DKIM record guards against forgery and modification of the emails you send from its email server. DKIM is an excellent tool for your business to build a trustworthy reputation by thwarting spoofing and phishing.
  • The bodies of emails remain unaffected. The header contains the information needed for validating and authenticating.
  • It works at the level of domain names. The DNS administrator signs all outgoing emails. Every user does not have to do that every time they send a message.
  • Additional security thanks to DMARC. More security tools are available that can help you become a better guard, such as the DMARC record. Additionally, the basis for it to function is a DKIM record.

Important DKIM TAGS

You will be able to use the following tags within the DKIM:

v – the DKIM’s version.

a – the employed signing algorithm is specified. It is compatible with RSA-SHA1 and RSA-SHA256.

b – a signature

bh – it stands for body hash.

c – Canonicalization of the message.

d – denotes the domain name.

h, header fields – this is a list of the signed header fields.

i – Unique identifier for the user or agent.

l – stands for body length.

q – DKIM’s default query method is DNS/TXT.

s – it denotes a selector.

t – is the signature timestamp.

x – the expiration date of the signature.

z – duplicated header fields.

Conclusion

Cybercriminals create spam and phishing campaigns by forging emails from reputable domains. So, hackers find it more challenging to impersonate businesses’ email domains, thanks to DKIM. Therefore, it’s crucial to comprehend and use this DNS record type. Best luck!

DNS Spoofing: Why is it so dangerous?

DNS Spoofing is an absolutely dangerous and harmful attack. In this article, we will explore its purpose, the different DNS Spoofing methods, and the ways to protect yourself against it. If this matches your desire, let’s start.

DNS Spoofing purpose

Cache poisoning, often known as DNS Spoofing, is a hacking attack. To respond to users’ queries by transmitting a forged record, such as a phony IP address, malicious DNS data or files (forged records, forged entries) are placed into the DNS cache of a resolution server. The goal is simple: redirect visitors to a site where attackers will attempt to steal users’ passwords and sensitive information.

The falsified data fools consumers’ devices into thinking they’re visiting the legitimate website they requested. Instead, they’re on their way to an unsafe location controlled by assailants. When users arrive, the website may resemble the one they expected. They are, however, in a forgery.

Methods types of DNS Spoofing

Attackers might employ a variety of strategies to achieve their illegitimate goals.

The purpose, as previously stated, is to redirect traffic to fake websites.

  • Poisining via DNS cache. In spam e-mails, corrupted code can be found in advertising, graphics, or URLs. Users’ devices are poisoned after they click the URL. After that, the malware directs users to fake websites.
  • Man-in-the-middle attack (spoofing DNS answers). This strategy aims to poison both the server and the user’s device simultaneously. The criminal is located between your browser and the DNS server in this case. Through software that injects the code, the communication is poisoned.
  • Hijack of a DNS server. The hacker gains access to the server, exploiting flaws, modifying its settings, adding a bogus entry, etc. What is the outcome? Every IP request that tries to access a specific website (the one that has been spoofed) will end up at the counterfeit website.

Prevention mechanisms

There are several techniques to defend yourself against such an attack. The following are a few of them:

  • Encryption. To keep DNS data, such as queries and responses, safe, encrypt it. A copy of the original web site’s security certificate cannot be forged.
  • Links that are unfamiliar to you. On the spur of the moment, don’t click on dubious URLs. These URLs are usually attached to spam or social media messages and come from unknown senders. By avoiding clicking on them, users may secure their data.
  • VPS (Virtual Private System) (VPN). Connecting to public networks carries more risks. You can safely interact with servers and communicate with domains using a VPN.
  • Detection. Use tools to analyze DNSSEC data received. It helps to authenticate data by employing digitally signed DNS records. As a result, DNSSEC ensures that DNS lookups are legitimate.
  • DNS cache. DNS data from frequently visited sites is retained for some time. As a result, it’s possible that only the user’s device, rather than the server, has been hacked. Cleaning the DNS cache regularly is a smart way to avoid the browser’s phony sites being routed.

Conclusion

Let’s review. DNS Spoofing can be highly inconvenient for both web users and site owners. An attacker’s primary motivation for carrying out a DNS Spoofing attack is either self-interest or the expansion of malware. DNS Spoofing impacts the server’s DNS registry, consciously rerouting the customer during a request to a suspicious IP address. How does your company defend itself from spoofing actions? By Encryption, Detection, VPS, etc.

Why is the DHCP server used?

The DHCP server is one of the really beneficial components when we are speaking for an extensive network. It can significantly reduce the number of errors made when a network administrator has to assign IP addresses manually. Let’s explain a little bit more about it and why it is used!

DHCP server – What does it mean?

The short DHCP server stands for Dynamic Host Configuration Protocol server. It is a server that automates different tasks and network configurations. This server relies on the standard DHCP protocol inside a particular network. Some examples of implementing the DHCP server are assigning Internet Protocol (IP) addresses to various devices, default gateways, subnet masks. 

Find out the differences between DNS and DHCP!

When you have a DHCP server, it is going to serve the queries of the clients automatically. Furthermore, it is going to provide them all required parameters and configurations to achieve communication on the network without any difficulties.

In case you don’t have a DHCP server, these kinds of tasks are going to be a responsibility of the network administrators. They will have to serve those requirements of clients to join the network, all of it performed manually. In more extensive networks, this could be a full-time job. 

Why use a DHCP server?

The process of supplying, administrating, and renewing IP addresses will become automated and dynamic. You just have to set up your particular preferences on the DHCP server. As a result, the process is going to operate without the need for any permanent further supervision.

Human mistakes are lead to a minimum, and automation helps with it. Every device, such as a smartphone or a computer that wants to connect successfully to a particular network requires a unique IP address. It is not possible for one IP address to work at the same time for several devices. 

The connection is not going to be achieved. Leases require to be monitored and renewed. Endpoints need to be modified, etc. Such tasks are capable of overwhelming the most prepared administrators if they have to perform them manually. The high number of demands can transcend them and lead to mistakes. Effectively this can be avoided with DHCP.

The process of configuring, modifying, and upgrading is pretty simple. The settings are going to be saved and propagate for everything to operate without any difficulties.

How does it work?

the Dynamic Host Configuration Protocol process has four main stages:

1. Discover. The client of the DHCP is going to distribute a message. This message includes information that it is on the network and that it requires an IP address.

2. Suggestion. The DHCP server receives the discover message from the client. It is going to proceed with suggesting an available IP address from the IP pool that this DHCP manages. 

3. Request. The client is going to get the DHCP offer for an IP address and also has to accept it. As the next step, the client sends a request to accept the given IP address back to the Dynamic Host Configuration Protocol server. 

4. Confirmation. The DHCP server receives the request. So it records it with details like, what IP address was given, to which MAC, and for how long. Then, it is going to confirm it and send the full network data required, such as DNS server, subnet mask, gateway, etc.