Mean Time to Respond

 MTTR (Mean Time to Respond)

Mean time to respond (MTTR) is the average time it takes to respond to a system failure or security incident after being alerted:

Definition

MTTR is the average time to respond to a system failure or security incident after being alerted. It's a critical metric for assessing an organization's incident response and recovery procedures.

Formula

To calculate MTTR, divide the response time (from alert to resolution) by the number of incidents.

Importance

A good understanding of IT security and a low MTTR is crucial for quickly identifying cyber threats and avoiding catastrophic consequences.

Related metrics

MTTR is similar to mean time to acknowledge (MTTA), but MTTR measures the time it takes to take specific responsive actions, while MTTA only measures the time it takes to recognize an alert.

Tips to reduce MTTR

Some tips to reduce MTTR include:

Integrating threat intelligence sources into security operations

Establishing clear communication channels

Fostering a culture of collaboration

Having strong cybersecurity measures in place

 Responsive Control

This is covered in the CompTIA CySA+ course.

"Responsive controls" in a Security Operations Center (SOC) refer to security measures implemented after a security incident has been identified and confirmed. They outline specific actions an analyst must take to mitigate the issue, often following a documented procedure within an incident response playbook.

Key points about responsive controls:

Action-oriented:

Unlike preventive controls that aim to stop an attack before it happens, responsive controls focus on taking immediate corrective actions once a breach is detected.

Playbook-driven:

To ensure consistency and efficiency, responsive actions are usually documented in a detailed incident response playbook, guiding analysts through necessary steps depending on the type of incident.

Examples of responsive actions:

Isolating a compromised system from the network

Quarantining a malicious file

Patching a vulnerable system

Resetting user passwords

Blocking suspicious IP addresses

Investigating the root cause of an incident

Restoring data from backups

 Clean Desk Policy

A clean desk policy is a set of guidelines requiring employees to keep their workspaces organized and free of clutter, especially when they are absent. The policy aims to protect sensitive information and reduce the risk of security breaches and data theft.

Some guidelines for a clean desk policy include:

Remove sensitive information

When an employee leaves their desk or when it is unattended, they should remove any sensitive or confidential materials and lock them away. This includes eliminating paper with sensitive information, such as account numbers and post-it notes.

Secure computers

Employees should shut down their computers at the end of the day to protect the data on the device and allow it to receive security updates.

Use electronic documents

Encourage employees to use electronic documents whenever possible.

Use shredders

Employees should use the official shredder bins or lockable confidential disposal bins to dispose of restricted or sensitive documents.

Erase whiteboards

Employees should erase a whiteboard when the meeting is over if a whiteboard contains sensitive information.

A clean desk policy can also help employees improve their time management, increasing productivity and a better work-life balance.

To implement a clean desk policy, organizations can:

Provide employees with access to tools like paper shredders and lockable file cabinets

Regularly remind employees about the policy

Ensure senior management is on board and adheres to the policy

Assign someone to enforce the policy

 False Positive

A "false positive" in vulnerability scanning refers to when a security tool incorrectly identifies a system as having a vulnerability, even though there is no actual security issue present, essentially raising a false alarm and wasting time investigating a non-existent threat; effectively, it means the scan reported a vulnerability that doesn't actually exist, requiring careful management to avoid unnecessary remediation efforts and maintain the accuracy of scan results.

Key points about false positives in vulnerability scanning:

Impact:

False positives can lead to wasted time and resources spent investigating non-existent vulnerabilities, potentially diverting attention away from real security issues.

Causes:

Overly broad scanning rules: When a scanner uses overly general detection criteria, it might flag benign configurations as vulnerabilities.

Incomplete information: If the scanner doesn't have access to all necessary information about a system, it might misinterpret certain aspects as vulnerabilities.

Outdated scanner logic: Older scanning tools may not be updated to recognize specific configurations that are no longer considered vulnerabilities.

Mitigating strategies:

Customizing scan profiles: Tailoring scan settings to the specific application or system being tested, including excluding known safe configurations.

Whitelisting: Defining known safe components or patterns to prevent false positives

Regular review and tuning: Regularly reviewing scan results and adjusting scanner settings to reduce false positives

Using advanced scanning tools: Utilizing tools with intelligent detection mechanisms that can better differentiate genuine vulnerabilities from false positives.

 CVSS Metrics

This is covered in the CompTIA CySA+ course.

Here are some examples of metrics used in the Common Vulnerability Scoring System (CVSS):

Attack Vector (AV)

How an attack can be executed, with higher scores for remote attacks:

Network (N): Remotely exploitable

Adjacent (A): Requires network adjacency for exploitation

Local (L): Not exploitable over a network

Physical (P): Requires physical interaction with the target system

Attack Complexity (AC)

How difficult it is to execute the attack:

Low: Easier to exploit

High: More challenging to exploit

Privileges Required (PR)

The level of access needed to exploit the vulnerability:

None: Unauthenticated

User Interaction (UI)

Whether the attacker needs to involve a user in the exploit:

Passive: The user needs to do something, like accidentally visiting a malicious website

Active: The user needs to do something, like executing a malicious office macro

Scope (S) indicates whether the exploit affects only the local security context

(U) Unchanged or not (C) Changed

Confidentiality (C)

High (H), Low (L), or None (N)

Integrity (I)

High (H), Low (L), or None (N)

Availability (A)

High (H), Low (L), or None (N)

Score Categories

Score                Description

0	None
0.1+	Low
4.0+	Medium
7.0+	High
9.0+	Critical

Here is a link to a CVSS calculator: https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator

This is covered in CompTIA CySA+.

 Amplification Attack

An amplification attack is a cyberattack in which an attacker exploits vulnerabilities in certain network protocols, like DNS or NTP, by sending small requests that trigger significantly larger responses from open servers. This effectively "amplifies" the traffic and overwhelms the intended target with a massive amount of data, often causing a denial-of-service (DoS) condition.

Key points about amplification attacks:

Exploiting protocol weaknesses:

These attacks rely on inherent protocol design flaws, allowing attackers to manipulate requests to generate significant responses from vulnerable servers.

Spoofing source IP:

To amplify the attack, attackers usually spoof the source IP address in their requests, ensuring a large response is sent to the intended victim instead of the attacker.

Commonly targeted protocols:

DNS (Domain Name System): A popular choice due to the enormous response size compared to the initial query.

NTP (Network Time Protocol): Can generate large-time synchronization responses.

CLDAP (Connectionless Lightweight Directory Access Protocol): Another protocol susceptible to amplification attacks.

Memcached: A database caching system that can be exploited for amplification attacks when improperly configured.

How an amplification attack works:

1. Sending small requests:

The attacker sends a small, crafted request to a vulnerable open server, often using a spoofed source IP address that points to the intended victim.

2. Large response generated:

Unaware of the spoofing, the server responds with a much larger data packet containing the requested information.

3. Traffic flood to the target:

This significant response is sent to the victim's IP address, creating a flood of traffic and potentially overwhelming the target's network resources.

Defense against amplification attacks:

Filtering at network perimeter:

Implementing network filters to block suspicious traffic based on source IP addresses and protocol types.

Rate limiting:

Configuring servers to limit requests from a single source within a specific time frame.

Proper server configuration:

Securing network services like DNS and NTP by limiting response sizes and filtering invalid requests.

Monitoring network traffic:

Actively monitoring network activity to detect unusual patterns indicative of an amplification attack.

Distributed Reflected Denial of Service

 DRDoS Attack

DRDoS, or Distributed Reflection Denial of Service, is a type of cyberattack that aims to make a network resource unavailable to its intended users. It is a more advanced form of a DDoS attack known as a Reflected DDoS attack.

In a DRDoS attack, a hacker spoofs the target's IP address and sends requests to a third-party server. The third-party server then sends its response to the target's IP address, which can significantly increase traffic. This can overwhelm the target's resources and make it difficult to trace back to the original attacker.

DNS servers, NTP servers (using the monlist command), and Memcached servers are some examples of services that can be used in a DrDoS attack.

Some potential consequences of a DrDoS attack include:

• Damage to relationships with partners, customers, and other stakeholders
• Reputational damage
• Revenue loss
• Operational downtime