An in depth look at the rootkit software

               An in depth look at the rootkit software

                                    (understanding the dark side of cybersecurity)

Introduction:

Rootkits are malicious computer programs that infiltrate a machine to gain administrative or system-level access.  Despite their clandestine nature, rootkits are merely designed to evade user authentication methods before delivering a malicious payload (i.e., they frequently coexist with trojans or other types of infections).

Rootkits have some autonomy since they outperform other infectors. Most are intended to automatically detect and exploit backdoors, or, if none exist, to rubber-stamp the installation of obsolete or defunct software. Of course, in some circumstances, criminal actors will actively exploit vulnerabilities before installing a rootkit on the victim's PC.

Understanding Rootkits: What Are They?

It refers to a malicious program that can illegally enter and acquire access to a computer network or system. On the other hand, rootkits are very capable of remaining hidden in a machine infected by them, unlike traditional malware. Most rootkits manipulate an OS’s kernel, which is the most important part of an operating system, to evade detection by antivirus software and security tools.

How Do Rootkits Work?

There are different methods utilized by rootkits as they invade and camouflage in a system. Exploiting software vulnerability is one of such method. They penetrate deep into the system so that it becomes hard to trace them. To guarantee that it stays operational throughout every system startup, some rootkits loads itself at boot-up stage.

Types of Rootkits:

Rootkits can be classified into several categories, each with its own set of characteristics: 

1. Kernel Mode Rootkits: Rootkits are capable of modifying the kernel of the operating system and this enables them to have total control over the entire system.

2. User Mode Rootkits: Rootkits of this type work on the application layer and are less difficult to detect than kernel mode rootkits.

3. Hardware/Firmware Rootkits: In particular, such rootkits work at the level of system BIOS or firmware. That is very hard to uninstall this because it remains in the system even after OS reinstallation.

4. Bootkits: One kind of rootkit is known as bootkits that manipulate or changes the Master Boot Record (MBR) of a PC so that the bootkit runs before the operating system starts.

Rootkit Detection:

Detecting and removing rootkits after an infiltration is difficult, owing to rootkits' ability to disrupt antivirus tools. Furthermore, after the rootkit has established a bridgehead, it can be used to whitelist processes associated with malicious software.The type of rootkit significantly influences the detection and eradication process. For example, most software-based rootkits can be recognized and then eliminated using behavioral or mem dump analysis. However, physically replacing the problematic components would not eliminate hardware-based rootkits. The same is true for kernel-level rootkits; although working on a software level, kernel rootkits cannot be uninstalled using the aforementioned approach and, in most circumstances, require an OS reinstall.Detection methods vary depending on the rootkit kind and penetration strategy: mem dump analysis, integrity checking, difference-based, behavioral-based, or using an alternate (trustworthy) medium.

1. Memory Dumps Analysis: Force-dumping virtual memory can help you discover most software-based rootkits, including those contained in Hyper-V. Mem dumps are only available offline, although they may also require access to internet code repositories.

2. Integrity checking: A PKI-based code-signing check can detect rootkits at the boot and kernel levels. The method compares a baseline hash output against a hash output computed at any point in time to identify whether or not the initial, publisher-signed file was tempered.

3. Difference-based Analysis: DA, or difference-based analysis, uses an API to compare raw and infected data. Raw data is generated from trusted sources (e.g., system pictures), whereas rootkit-infected data is generated by an API specifically built for this task.

Some well-known rootkit examples include:

Most cybercriminals do not code their own malware. Instead, they just use previously existing dangerous applications. Most of the time, they only adjust the rootkit's settings, although sometimes technically skilled persons install their code. This is known as the malware economy and is a worthwhile read. Some virus has a higher market share than others, just as it does in the real economy. In this section, we'll look at a few of the most popular rootkit families. If you are unfortunate enough to become infected with a rootkit, it is almost certainly one of them.

1. ZeroAccess rootkit: This software is responsible for the ZeroAccess botnet, which drains your resources while mining bitcoins or conducting click fraud by spamming you with ads. At one point, security researchers estimated that the ZeroAccess botnet contained 1-2 million computers. Microsoft, together with other security businesses and authorities, took down a major portion of it (but not all, regrettably). While the ZeroAccess rootkit is no longer a significant threat, variations of it are still available and actively deployed.

2. TDSS /Alureon/TDL: The TDSS rootkit-based botnet was formerly estimated to be the world's second largest. Following some intensive law enforcement measures, some arrests were made, and the botnet began to diminish. However, the virus code is still available and being used. TDSS, unlike the ZeroAccess rootkit, seeks your personal information, such as credit card information, online bank accounts, passwords, Social Security numbers, and so on.

3. Necurs: The rootkit driving Necurs, one of the largest currently operating botnets, is responsible for the distribution of vast volumes of Locky ransomware spam as well as Dridex financial malware.The Necurs rootkit protects other types of malware that enslave computers to the botnet, preventing the infection from being eradicated.Unlike TDSS and ZeroAccess, Necurs is an active botnet, and its operators are still actively striving to spread it.

The consequences of a rootkit infection can be severe: 

1. Data Theft: Rootkits can take away confidential data including login       credentials, financial details, and private files without knowledge of the users.

2. Unauthorized Access: Once a system is compromised with a rootkit, cyber criminals may effectively control its operations and utilize it to commit felonies or perpetrate new intrusions.

3. System Instability: This can destabilize a system and result in crashes, slow downs or unresponsiveness of the same system.

4. Evasion of Security Measures: Rootkits are capable of disabling antivirus software and other security utilities, therefore it becomes hard to detect and delete them.

Protecting Against Rootkits:

Preventing rootkit infections requires a multi-faceted approach: 

1. Regular Software Updates: Updating the Operating System and all installations software ensures that there are no known vulnerabilities that can be used by rootkit programs.

2. Antivirus and Anti-Malware Tools: Using reliable security software can detect and remove rootkits in their preliminary stage.

3. Network Security: This could be achieved by setting up strong firewalls and intrusion detection system that would effectively bar any unauthorised access.

4. User Awareness: Users can avoid rootkit infestation by educating them on the safest possible online behaviours such as refraining from suspect downloads or links.

Conclusion:

Rootkits represent a significant challenge in the realm of cybersecurity. As cybercriminals continue to evolve their techniques, understanding the intricacies of rootkit software becomes paramount. By staying informed and implementing robust security practices, individuals and organizations can reduce the risk of falling victim to these stealthy and dangerous threats, ensuring a safer digital environment for everyone.

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