An active attack is a dangerous cyberattack because it attempts to alter your computer network’s resources or operations. Active attacks often result in undetected data loss, brand damage, and an increased risk of identity theft and fraud.

Active attacks represent the highest priority threat facing enterprises today. Fortunately, there are things you can do to prevent these attacks and mitigate the effects if they occur.

What Are Active Attacks?

In an active attack, threat actors exploit weaknesses in the target’s network to gain access to the data therein. These threat actors may attempt to inject new data or control the dissemination of existing data.

Active attacks also involve making changes to data in the target’s device. These changes range from theft of personal information to a complete network takeover. You are often alerted that the system has been compromised as these attacks are easily detectable, but stopping them once they’ve started can be quite tasking.

Small and medium-sized businesses, commonly known as SMBs, usually bear the brunt of active attacks. This is because most SMBs do not have the resources to procure high-end cybersecurity measures. And as active attacks continue to evolve, these security measures must be updated regularly, or they leave the network vulnerable to advanced attacks.

How Does an Active Attack Work?

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The first thing threat actors will do after identifying the target is to look for vulnerabilities within the target’s network. This is a preparatory stage for the type of attack they are planning.

They also use passive scanners to get information about the type of programs running on the target’s network. Once the weaknesses have been discovered, the hackers may use any of the following forms of active attacks to undermine network security:

1. Session Hijacking Attack

In a session hijacking attack, also known as session replay, playback attacks, or replay attacks, the threat actors copy the internet session ID information of the target. They use this information to retrieve login credentials, impersonate the targets, and further steal other sensitive data from their devices.

This impersonation is done using session cookies. These cookies work together with HTTP communication protocol to identify your browser. But they remain in the browser after you have logged out or ended the browsing session. This is a vulnerability that threat actors exploit.

They recover these cookies and fool the browser into thinking you’re still online. Now, hackers can get whatever information they want from your browsing history. They can easily get credit card details, financial transactions, and account passwords this way.

There are other ways hackers can obtain the session ID of their target. Another common method involves using malicious links, leading to sites with a ready-made ID which the hacker can use to hijack your browsing session. Once seized, there would be no way for the servers to detect any difference between the original session ID and the other replicated by the threat actors.

2. Message Modification Attack

These attacks are mainly email-based. Here, the threat actor edits packet addresses (containing the sender and recipient’s address) and sends the mail to a completely different location or modifies the content to get into the target’s network.

The hackers commandeer mail between the target and another party. When this intercept is complete, they have the liberty to perform any operation on it, including injecting malicious links or removing any message within. The mail will then continue on its journey, with the target not knowing it has been tampered with.

3. Masquerade Attack

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This attack exploits weaknesses in the authentication process of the target’s network. The threat actors use stolen login details to impersonate an authorized user, using the user’s ID to gain access to their targeted servers.

In this attack, the threat actor, or masquerade, could be an employee within the organization or a hacker utilizing a connection to the public network. Lax authorization processes might allow these attackers entry, and the amount of data they would have access to depends on the privilege level of the impersonated user.

The first step in a masquerade attack is using a network sniffer to obtain IP packets from the target’s devices. These spoofed IP addresses fool the target’s firewalls, bypassing them and gaining access to their network.

4. Denial-of-Service (DoS) Attack

In this active attack, the threat actors make network resources unavailable to the intended, authorized users. If you experience a DoS attack, you will be unable to access the network’s information, devices, updates, and payment systems.

There are various types of DoS attacks. One type is the buffer overflow attack, where the threat actors flood the target’s servers with much more traffic than they can handle. This causes the servers to crash, and as a result, you will not be able to gain access to the network.

There is also the smurf attack. The threat actors will use completely misconfigured devices to send ICMP (internet control message protocol) packets to several network hosts with a spoofed IP address. These ICMP packets are typically used to determine whether data is reaching the network in an orderly manner.

The hosts that are the recipients of these packets will send messages to the network, and with many responses coming in, the result is the same: crashed servers.

How to Protect Yourself Against Active Attacks

Active attacks are commonplace, and you should protect your network from these malicious operations.

The first thing you should do is install a high-end firewall and intrusion prevention system (IPS). Firewalls should be part of any network’s security. They help scan for suspicious activity and block any that is detected. IPS monitors network traffic like firewalls and takes steps to protect the network when an attack is identified.

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Another way to protect against active attacks is using random session keys and one-time passwords (OTPs). Session keys are used to encrypt communication between two parties. Once communication ends, the key is discarded, and a new one is generated randomly when another communication commences. This ensures maximum security, as each key is unique and cannot be replicated. Furthermore, when a session has ended, the key for that period can’t be used to assess the data exchanged during the session.

OTPs work on the same premise as session keys. They are randomly generated alphanumeric/numeric characters that are valid for one purpose only and expire after a specific period. They are often used in combination with a password to provide two-factor authentication.

Hackers and Attackers, Firewalls and 2FA

Active attacks exploit the weaknesses in a network’s authentication protocols. Therefore, the only proven way to prevent these attacks is to use firewalls, IPS, random session keys, and, most importantly, two-factor authentication. Such authentication can be a combination of a randomly generated key, a username, and a password.

This might seem tedious, but as active attacks evolve and become even more ruthless, verification processes should rise to the challenge, standing guard against these incoming attacks. Remember that once the threat actors are in your network, it would be difficult to flush them out.