ADMIN Network & Security January/February 2023의 목차

Whereas IT organizations in the past maintained individual setups with separate infrastructures, scalable platforms today almost inevitably set the tone. Because customers take it for granted that their providers will continually reduce the cost of IT infrastructure and its operation, today IT can only be operated efficiently if it relies on sheer mass. In the past, admins might have had a few dozen systems in their care; however, today they are more likely to have hundreds of machines or even more. Of course, this also affects the applications that run on these platforms: They need to be able to grow along with the environments. Several examples do this impressively, including Ceph, which offers storage that grows with the usage scenario, or applications that adhere to a cloudready design and can…

Installing and uninstalling applications in Windows traditionally involves running a graphical wizard. Unattended installs that depend on this type of installer are often troublesome. In comparison, installing an application on Linux is usually a piece of cake: Package managers such as Apt, Yum, and Zypper make sure that the sources are always up to date and resolve dependencies, and they usually do not require any parameters apart from the package name. However, Windows users also have some practical command-line interface (CLI) based package management tools. In this article, I look at two solutions for full-fledged package managers on Windows: Chocolatey and Microsoft’s WinGet. Unique Installs If you want to install a simple Windows program such as 7-Zip, Green-Shot, or Notepad++, you usually download and launch the installer (EXE or MSI)…

Data has a central function in the digital economy. It is collected in gigantic quantities so that automated or autonomous decisions can be made on the basis of data analysis. In this context, data security is achieved by technologies such as encryption, access protection, and tools that prevent attacks (e.g., SQL injection) on information. In contrast, data governance involves tools that encourage correct handling of data (e.g., managing personal and other sensitive information) and that implement the associated risk management with the use of, for example, metrics and control instruments. The Basis: Data Overview To implement data security, not just as a local solution for certain databases but to secure all or at least a large amount of relevant information, you first need to establish the basis. Data management informs…

If you want to know exactly what operations a program on your computer performs, you have several ways to find out. One obviously simple method is to investigate the source code of the file, if available. You can do so easily with scripting languages like Python or open source software, but if programs are translated into bytecode before delivery, your job is a little more complicated. Various tools are involved in converting code into an executable program: in most cases, at least a compiler and a linker. From the commands in a programming language, the compiler creates the machine language. In doing so, it optimizes the execution sequence or individual operations, depending on the configuration, to a greater or lesser extent, which can ultimately have a major effect on the…

Today, it hardly matters which operating systems are used on servers; the malware developers working in the background cover all the popular systems. Even specialist operating systems such as the VMware ESXi hypervisor have repeatedly been targeted by criminals. This article sheds light on the damage potential, pointing out ways to mitigate risk and actions to help prepare for an incident. In many cases, you will hear about the benefits of virtualization, the added security that isolating individual machines can provide, and how easy it is to revert to previous versions at any time with snapshots. Modern ransomware and the behavior of the groups behind it have adapted to this kind of reasoning and the technology behind it. Today, malware is installed well ahead of the attack. The overhead required…

Even in the cloud age, a classic IT task is operating databases. In addition to SQL relational databases, non-relational databases are making inroads into the corporate landscape. Today, companies likely use more than just one kind of database. In principle, cloud databases can be operated in the same way as databases in an organization’s data center. The admin team simply installs the database as a virtual machine. Administration in this case is no different from local administration. Aspects such as high availability, patching, backup and restore, disaster recovery, and scaling remain the administrator’s responsibility. To make it as easy as possible for companies to operate databases, cloud providers also offer databases as managed services, which means the customer is, by and large, only responsible for the application and the database…

If you want to respond to higher load with more instances instead of a more powerful server, you typically need stateless applications. Horizontal scaling, whether in the cloud or with multiple servers, virtual machines, Kubernetes pods, or containers, creates the elasticity and resilience that business applications need – especially in the cloud, where every component needs to be replaceable in the event of failure and where elasticity ensures cost reductions without performance loss. Hardly any application can do without a database to store data and ensure consistency, even with concurrent transactions. However, a database is likely to be stateful, and that presents a challenge when it comes to scaling. YugabyteDB is a cloud-native database, is fully open source, and aims to achieve PostgreSQL compatibility, which means the ability to run…

In the Microsoft 365 environment, with its variety of configurations and multiple tenants to manage, Desired State Configuration (DSC) is an ideal way to track changes and reset a configuration to the desired state. Microsoft provides a great deal of information about the project [1], but in my experience, some of it is outdated. This article refers to the version available March 2022. Preparations for DSC Before setting up Microsoft 365 DSC (M365DSC), you need to create an Azure Active Directory (Azure AD) application that you will use later to authenticate the PowerShell script. Alternatively, you could log in with a username and password; I will look at the advantages and disadvantages of these methods in detail. When authenticating with an Azure AD application, you use either a certificate you create…

Cyberattacks are constantly on the rise, and ransomware is spreading rapidly. As a result, corporations also need to update their security strategies constantly. And it is better to fight against aggressors together than go it alone, according to CrowdSec [1], an open source cloud service and participative intrusion protection system (IPS) capable of analyzing the behavior of systems and providing a customized response to attacks. The tool acts as a community, sharing attack intelligence and fighting cyber criminals together. In this way, corporations can rely on data from the entire community to protect their servers, and not just on information obtained from their enterprise. Information can come from syslogs, CloudTrail events, security information and event management (SIEM) systems, and other sources (e.g., from firewalls or the event viewer of Windows…

Companies spend huge amounts of money on preventing threats and ensuring data confidentiality caused by home office and distributed working practices. Microsoft has also identified this market and, in addition to Endpoint Protection in Microsoft 365, offers the comprehensive Purview Compliance Manager designed to prevent the outflow of confidential data through data loss prevention. Microsoft Purview The Microsoft Compliance Center has been around for a while, but it was renamed Microsoft Purview in April 2022. With Purview, Microsoft combines compliance with data governance, primarily to accommodate the new hybrid working world, where connectivity is required all the time, wherever people happen to be. Documents are exchanged flexibly and are no longer simply transmitted by email, but by instant messaging tools such as Teams or OneDrive. The result is data fragmentation…

Opinions are divided into two major camps as to what constitutes a cloud database. The first camp claims they are databases provided by hyperscalers such as Amazon, Azure, and Google under the database as a service (DBaaS) model. The other, more common, view is that they can be any database that someone deploys within any cloud infrastructure, whether it be a private cloud, public cloud, hybrid cloud, multicloud, or hosted DBaaS. It’s just a matter of where the data is stored and how it is accessed. In the case of on-premises databases, access is over the corporate network (and VPN, if necessary) to internal database servers, whereas cloud databases will rely on Internet connections to external (in some cases internal) cloud servers. Deployment Models Generally speaking, cloud databases have three…

Misconfiguration has long been a major problem in the IT world. Any admin can recall a scenario in which Dev did something, QA did another thing, and other departments did their own thing to pass the software through its stages of delivery. Finally, the product fails because of unknown manual tricks and black magic. Who could forget the time wasted in painful war room sessions, always wondering and struggling to reason about the weird failures? In fact, misconfiguration has been identified as the root cause for many recent public cloud outages – even for the tech giants like Amazon and Google. Listing 1: Dockerfile_ServerBase FROM ubuntu:22.04 How do you solve config misconfiguration and parity issues in the modern cloud-driven IT world? Open source solutions come to the rescue. In this…

In the Microsoft world of Azure and Microsoft 365, especially, Azure Active Directory (AD) is an important component for authenticating users. By synchronizing with Active Directory, organizations can also synchronize onpremises credentials to the cloud, enabling single sign-on (SSO) scenarios. As with Active Directory, you need to keep accounts in Azure AD organized and delegate the management of various tasks. Organizational units (OUs) are used for this purpose in Active Directory; Azure AD has something similar to OUs called administrative units (AUs). In this article I’ll show you how to work with AUs for a better way to delegate cloud directory authorizations. Although in general the AUs in Azure AD correspond to the OUs in Active Directory, the two differ significantly. In contrast to AD, the authorization structures in Azure AD…

Every admin knows group policies inside out. Group policy objects (GPOs) are still the most effective means of centrally managing and, above all, protecting clients. They play a crucial role, especially when it comes to protection against ransomware. Generally speaking, Windows Server 2022 reveals no technical innovations in the area of group policies for local installations. The GPO infrastructure and the available feature set are static, with no more development in this area. However, some innovation and change is emerging in the cloud, but only if you sign up for the right plan. Still, there’s nothing out of the box in a plain vanilla Azure Active Directory (AD) that controls the client as extensively as group policies can locally. With this in mind, I look at new or changed approaches…

In the Performance Tuning Dojo article two issues ago [1], I determined the importance of baselines to every performance analysis. This month, I measure a baseline on the cloud and confirm it meets my expectations – and discuss what to do in light of unexpected surprises. Network performance is a complex problem with many variables. To make the problem tractable, you start by looking at specific scenarios, as opposed to the entire problem space in abstract. What does network performance look like in AWS Elastic Compute Cloud (EC2) when using familiar tools? Amazon’s Network At its simplest, networking in AWS is straightforward: Launching an instance with the default networking configuration will give you an instance with a valid IP address. At a minimum, an AWS instance has one network device…