Social engineering is the term used for a broad range of malicious activities accomplished through human interactions. It uses psychological manipulation to trick users into making security mistakes or giving away sensitive information.

Social engineering attacks typically involve some form of psychological manipulation, fooling otherwise unsuspecting users or employees into handing over confidential or sensitive data. Commonly, social engineering involves email or other communication that invokes urgency, fear, or similar emotions in the victim, leading the victim to promptly reveal sensitive information, click a malicious link, or open a malicious file. Because social engineering involves a human element, preventing these attacks can be tricky for enterprises.

True Positive - IDS referring a behavior as an attack, in real life it is

True Negative - IDS referring a behavior not an attack and in real life it is not

False Positive - IDS referring a behavior as an attack, in real life it is not

False Negative - IDS referring a behavior not an attack, but in real life is an attack.

False Negative - is the most serious and dangerous state of all !!!!

Most likely have an issue with DNS.

DNS stands for “Domain Name System.” It’s a system that lets you connect to websites by matching human-readable domain names (like example.com) with the server ' s unique ID where a website is stored.

Think of the DNS system as the internet’s phonebook. It lists domain names with their corresponding identifiers called IP addresses, instead of listing people’s names with their phone numbers. When a user enters a domain name like wpbeginner.com on their device, it looks up the IP address and connects them to the physical location where that website is stored.

NOTE:  Often DNS lookup information will be cached locally inside the querying computer or remotely in the DNS infrastructure. There are typically 8 steps in a DNS lookup. When DNS information is cached, steps are skipped from the DNS lookup process, making it quicker. The example below outlines all 8 steps when nothing is cached.

The 8 steps in a DNS lookup:

1. A user types ‘example.com’ into a web browser, and the query travels into the Internet and is received by a DNS recursive resolver;

2. The resolver then queries a DNS root nameserver;

3. The root server then responds to the resolver with the address of a Top-Level Domain (TLD) DNS server (such as .com or .net), which stores the information for its domains. When searching for example.com, our request is pointed toward the .com TLD;

4. The resolver then requests the .com TLD;

5. The TLD server then responds with the IP address of the domain’s nameserver, example.com;

6. Lastly, the recursive resolver sends a query to the domain’s nameserver;

7. The IP address for example.com is then returned to the resolver from the nameserver;

8. The DNS resolver then responds to the web browser with the IP address of the domain requested initially;

Once the 8 steps of the DNS lookup have returned the IP address for example.com, the browser can request the web page:

9. The browser makes an HTTP request to the IP address;

10. The server at that IP returns the webpage to be rendered in the browser.

NOTE 2:  DNS primarily uses the User Datagram Protocol (UDP) on port number 53 to serve requests. And if this port is blocked, then a problem arises already in the first step. But the ninth step is performed without problems.

A Wireless Intrusion Prevention System (WIPS) is a network device that monitors the radio spectrum for the presence of unauthorized access points (intrusion detection), and can automatically take countermeasures (intrusion prevention).

Internet of Medical Things (IoMT) devices are internet-connected medical devices that can collect, transfer, and analyze data over a network. They can provide improved patient care and comfort, but they also pose security challenges and risks, as they can be targeted by cyberattacks, such as ransomware, that can compromise their functionality, integrity, or confidentiality. Ransomware is a type of malware that encrypts the victim’s data or system and demands a ransom for its decryption or restoration. Ransomware attacks can cause serious harm to healthcare organizations, as they can disrupt their operations, endanger their patients, and damage their reputation.

To protect IoMT devices from ransomware attacks, the main recommendation is to use network segmentation to isolate IoMT devices from the main network. Network segmentation is a technique that divides a network into smaller subnetworks, each with its own security policies and controls. Network segmentation can prevent or limit the spread of ransomware from one subnetwork to another, as it restricts the communication and access between them. Network segmentation can also improve the performance, visibility, and manageability of the network, as it reduces the network congestion, complexity, and noise.

The other options are not as effective or feasible as network segmentation. Implementing multi-factor authentication for all IoMT devices may not be possible or practical, as some IoMT devices may not support or require user authentication, such as sensors or monitors. Disabling all wireless connectivity on IoMT devices may not be desirable or realistic, as some IoMT devices rely on wireless communication protocols, such as Wi-Fi, Bluetooth, or Zigbee, to function or transmit data. Regularly changing the IP addresses of all IoMT devices may not prevent or deter ransomware attacks, as ransomware can target devices based on other factors, such as their domain names, MAC addresses, or vulnerabilities.  References :

What Is Internet of Medical Things (IoMT) Security?

5 Steps to Secure Internet of Medical Things Devices

Ransomware in Healthcare: How to Protect Your Organization

[Network Segmentation: Definition, Benefits, and Best Practices]

To ensure both confidentiality and non-repudiation for secure email communication, you need to use a combination of symmetric and asymmetric cryptography. Symmetric encryption is a method of encrypting and decrypting data using the same secret key, which is faster and more efficient than asymmetric encryption. Asymmetric encryption is a method of encrypting and decrypting data using a pair of keys: a public key and a private key, which are mathematically related but not identical. Asymmetric encryption can provide authentication, integrity, and non-repudiation, as well as key distribution.

The cryptographic technique that would best serve the purpose is to apply asymmetric encryption with RSA and use the private key for signing. RSA is a widely used algorithm for asymmetric encryption, which is based on the difficulty of factoring large numbers. RSA can be used to encrypt data, as well as to generate digital signatures, which are a way of proving the identity and authenticity of the sender and the integrity of the message.

The steps to implement this technique are as follows 1 :

Generate a pair of keys for each user: a public key and a private key. The public key can be shared with anyone, while the private key must be kept secret and protected by the user.

When a user wants to send an email to another user, they first encrypt the email content with a symmetric key, such as AES, which is a strong and efficient algorithm for symmetric encryption. The symmetric key is then encrypted with the recipient’s public key, using RSA. The encrypted email and the encrypted symmetric key are then sent to the recipient.

The sender also generates a digital signature for the email, using their private key and a hash function, such as SHA-256, which is a secure and widely used algorithm for generating hashes. A hash function is a mathematical function that takes any input and produces a fixed-length output, called a hash or a digest, that uniquely represents the input. A digital signature is a hash of the email that is encrypted with the sender’s private key, using RSA. The digital signature is then attached to the email and sent to the recipient.

When the recipient receives the email, they first decrypt the symmetric key with their private key, using RSA. They then use the symmetric key to decrypt the email content, using AES. They also verify the digital signature by decrypting it with the sender’s public key, using RSA, and comparing the resulting hash with the hash of the email, using the same hash function. If the hashes match, it means that the email is authentic and has not been tampered with.

Using this technique, the email communication is secure because:

The confidentiality of the email content is ensured by the symmetric encryption with AES, which is hard to break without knowing the symmetric key.

The symmetric key is also protected by the asymmetric encryption with RSA, which is hard to break without knowing the recipient’s private key.

The non-repudiation of the email is ensured by the digital signature with RSA, which is hard to forge without knowing the sender’s private key.

The digital signature also provides authentication and integrity of the email, as it proves that the email was sent by the sender and has not been altered in transit.

References :

How to Encrypt Email (Gmail, Outlook, iOS, Yahoo, Android, AOL)