Intrusions and Viruses, Firewalls, Intrusion Detection.

What are Intrusions? 

Intrusions, also known as security breaches or cyberattacks, occur when unauthorized individuals or entities gain access to computer systems, networks, or data without permission. These intruders may have malicious intent, such as stealing sensitive information, disrupting services, or causing damage. Detecting and preventing intrusions is a critical aspect of maintaining the security and integrity of digital systems. 

Types of Intrusions

 1.External Intrusions

  2.Internal Intrusions

1.External Intrusions: External intrusions, also known as external cyberattacks or external security breaches, refer to unauthorized access and malicious activities initiated by attackers from outside an organization's network or systems. These intrusions can target a wide range of entities, including businesses, government agencies, and individuals. The goal of external intrusions is often to compromise data, steal sensitive information, disrupt services, or cause damage to the targeted organization. 

• • Brute Force Attacks: A brute force attack is a cybersecurity attack method in which an attacker attempts to gain access to a system, network, or account by systematically trying all possible combinations of passwords or encryption keys until the correct one is found. This method relies on the attacker's ability to automate the process of trying numerous combinations quickly and efficiently.

  • Denial of Service (DoS) Attacks: Attackers overwhelm a system with excessive traffic or requests, causing it to become unavailable.

  • Phishing: Attackers use deceptive emails or websites to trick users into revealing sensitive information, such as login credentials.

2.Internal Intrusions: Internal intrusions, also known as insider threats, occur when individuals with authorized access to an organization's systems, networks, or data misuse their privileges for malicious purposes. Unlike external intrusions, which involve attackers from outside the organization, internal intrusions involve individuals who are already part of the organization. These individuals could be employees, contractors, partners, or anyone with legitimate access to the organization's resources. 

Internal intrusions can be particularly damaging due to the insider's familiarity with the organization's systems, processes, and sensitive information. There are two main categories of insider threats: 

• • Malicious Insiders: These are individuals who intentionally misuse their access for personal gain, harm the organization, or engage in activities that are against the organization's interests. Motivations for malicious insiders can include financial gain, revenge, ideology, or a desire to sell sensitive information.

  • Negligent Insiders: Negligent insiders are individuals who unintentionally cause security breaches due to carelessness, lack of awareness, or inadequate training. They might inadvertently share sensitive information, click on phishing emails, or mishandle data.

Examples of Internal Intrusions:

1.Data Theft: An employee with access to sensitive customer information steals this data to sell or use for personal gain.

2.Sabotage: A disgruntled employee intentionally disrupts critical systems or services to cause harm to the organization.

3.Unauthorized Access: An insider uses their privileges to access information or systems beyond their job responsibilities.

4.Unintentional Data Exposure: An employee inadvertently sends sensitive information to the wrong recipients or leaves confidential documents in a public area.

5.Insider Trading: In the context of financial markets, employees or individuals with access to confidential financial information trade securities based on that information before it becomes public.

Mitigating Internal Intrusions:

To address internal intrusions, organizations can implement the following measures:

1.Access Controls: Implement the principle of least privilege, where individuals are given the minimum access required to perform their job tasks.

2.User Monitoring: Implement monitoring systems that track and log user activities to detect unusual or unauthorized behavior.

3.User Behavior Analytics: Use advanced analytics to detect anomalies in user behavior that might indicate malicious intent.

4.Regular Training: Provide cybersecurity awareness training to employees to educate them about security best practices and the potential risks of insider threats.

5.Whistleblower Programs: Establish mechanisms for employees to report suspicious activities without fear of retaliation.

6.Separation of Duties: Divide tasks and responsibilities among multiple individuals to prevent a single individual from having excessive control.

7.Data Loss Prevention (DLP): Implement DLP tools to monitor and control the movement of sensitive data within and outside the organization.

8.Incident Response Plan: Develop a plan to respond to insider threats, including protocols for investigating and addressing incidents.

By combining technical controls, policies, user education, and monitoring, organizations can reduce the risk of internal intrusions and effectively manage insider threats to their systems, data, and operations.

Virus(Vital Information Resources Under Sieze)

Essential Information Compromised: A computer virus is a piece of code or software that can have detrimental effects on your computer data by either corrupting or completely destroying it. These viruses can rapidly create copies of themselves and distribute them throughout various folders, resulting in harm to your computer's data. In reality, a computer virus is a form of malicious software or "malware" that, upon infecting your system, duplicates itself by altering other computer programs and implanting its own code. 

The methods through which viruses impact computers and devices include:

• Downloading Files Online: When files are downloaded from the internet, viruses can infiltrate and infect the system.

• Media or Drive Removal: Viruses can spread when removable media or drives are connected to infected systems and then introduced to other devices.

• Pen Drives: Infections can occur through the use of infected pen drives or USB devices, which carry the virus from one system to another.

• Email Attachments: Viruses often arrive as attachments in emails, allowing them to enter systems once the attachments are opened.

• Unpatched Software & Services: Vulnerabilities in software and services that haven't been updated with the latest patches can be exploited by viruses.

• Weak Administrator Passwords: Viruses can take advantage of weak or unprotected administrator passwords to gain unauthorized access and spread.

The effects of a virus on a computer system include:

• Disruption of Normal Functionality: Viruses can interfere with the regular operations of the targeted computer system.

• Disruption of Network Usage: The presence of a virus can disrupt the system's ability to access and use network resources.

• Alteration of Configuration Settings: Viruses can modify the settings and configurations of the system, potentially leading to instability and unexpected behavior.

• Data Destruction: Viruses can destroy or corrupt data stored on the infected computer, causing irreversible loss.

• Disruption of Network Resources: The virus's impact can extend to disrupting resources shared across a computer network.

• Confidential Data Destruction: Viruses can target and destroy sensitive and confidential data, jeopardizing privacy and security

A computer virus attack can manifest through several noticeable signs. Here are a few examples:

• Increased Pop-Up Windows: You might experience a surge in pop-up windows appearing on your screen. These pop-ups could urge you to visit unfamiliar websites or prompt you to download software, potentially malicious.

• Homepage Alteration: Your usual homepage could be replaced by a different website without your consent. Moreover, you might find it challenging to restore your original homepage settings.

• Unauthorized Email Activity: Your email account might exhibit abnormal behavior, such as sending out a large number of emails without your knowledge. Criminals could gain control over your account or manipulate it to send emails from another compromised computer.

• Frequent System Crashes: A virus can cause significant harm to your hard drive, resulting in device freezes or crashes. In severe cases, your device might not restart at all.

• Unusual Sluggishness: If your computer's processing speed suddenly decreases, it could indicate the presence of a virus affecting its performance.

• Unrecognized Startup Programs: You might notice unfamiliar programs launching when you start your computer. This anomaly could become evident as you power up your device or by reviewing the list of active applications.

• Unexpected Activities like Password Changes: Unauthorized actions, such as changes to your passwords, can occur due to a virus attack. This may lead to difficulties in accessing your computer.

A firewall is a network security device or software application that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Its main purpose is to establish a barrier between a trusted internal network and untrusted external networks, such as the internet, to prevent unauthorized access and protect sensitive data.

Firewalls work by examining network packets and applying rules to determine whether to allow or block the traffic. There are several types of firewalls, each with its own approach to filtering traffic:

1.Packet Filtering Firewall: This type of firewall examines packets of data and compares their attributes, such as source and destination IP addresses, port numbers, and protocol types, against a set of predefined rules. It then decides whether to allow or deny the packet based on these rules.

2.Stateful Inspection Firewall: Also known as dynamic packet filtering, this firewall not only considers individual packets but also keeps track of the state of active connections. It monitors the state of connections and ensures that only legitimate traffic associated with an established connection is allowed through.

3.Proxy Firewall: A proxy firewall acts as an intermediary between internal and external networks. It receives and forwards traffic on behalf of the internal network, effectively hiding internal network details. This adds an extra layer of security by preventing direct connections between external entities and the internal network.

4.Application-layer Firewall: This type of firewall operates at the application layer of the OSI model. It can understand specific application protocols and make decisions based on the actual content of the traffic. This allows for more granular control and the ability to block or allow specific application functions or commands.

5.Next-Generation Firewall (NGFW): NGFWs combine traditional firewall functionality with additional features such as intrusion detection and prevention, deep packet inspection, and application awareness. They aim to provide more advanced threat detection and prevention capabilities.

6.Unified Threat Management (UTM): UTM appliances integrate multiple security features into a single device. These features can include firewalling, antivirus, intrusion detection/prevention, content filtering, and more.

Firewalls can be deployed at various points within a network architecture, including:

• Perimeter/Front-end Firewalls: These protect the network from external threats, typically placed at the boundary between an internal network and the internet.

• Internal Firewalls: Placed within the internal network, these segment different parts of the network to contain potential breaches and limit the spread of threats.

• Host-based Firewalls: Installed on individual devices (such as computers or servers), these firewalls control traffic at the device level and can be customized for specific security needs.

The classification of a firewall as either hardware or software can be a source of confusion. As previously mentioned, firewalls exist in both forms: as network security devices and as software applications on computers. Thus, the distinction between the two isn't absolute, and having both can be beneficial.

While hardware and software firewalls share the same goal, they function differently due to their respective formats. A hardware firewall is a tangible device situated between a computer network and a gateway, like a broadband router. Conversely, a software firewall is a program installed on a computer, operating through port numbers and interactions with installed software.

Additionally, there are cloud-based firewalls often referred to as Firewall-as-a-Service (FaaS). One key advantage of these cloud-based solutions is their centralized management. Similar to hardware firewalls, cloud-based options excel at delivering perimeter security.

In essence, the distinction between hardware and software firewalls isn't always clear-cut, as both forms contribute to network security, albeit through varying mechanisms.

Difference between a Firewall and Anti-virus.