Posts

“How much does a security audit cost?” – I hear that question almost as often as “Do we even need one?”. The honest answer upfront: There is no serious fixed price – and that is a good thing. Here is why audit effort varies so much, how prices actually form, and what a good offer looks like. What drives the effort of an audit A security audit is not a standard product. Four factors decide how much work goes into it: ...

“Should we get an audit or a pentest?” – the question comes up again and again, and honestly: the answer is less often “simply both” than you might think. The two approaches answer different questions. Understand that, and you also know where to start. What a security audit checks A security audit is a systematic technical assessment: I look at your configurations, architectures, processes, and settings – cloud setup, Linux and container environments, access rights, secrets, monitoring. The goal is to find and assess known vulnerabilities, misconfigurations, and design problems. ...

“What does a pentest cost?” is the most common question after “what is a pentest?” – and it is a fair one. The honest answer up front: there is no serious fixed price. Anyone offering you pentests “from” a certain amount is calculating at a risk – yours. Here is how prices for security services actually come about, and how to recognise a good proposal. Why there is no fixed price A pentest (or a security audit) is not a standard product like a firewall license. The effort depends on things that differ completely from business to business: ...

The good news first: most ransomware cases are not decided during the attack, but during recovery. Companies with usable backups and a rehearsed recovery get away with a bad weekend. Those without end up negotiating ransom demands. The difference lies in a handful of decisions made in advance – and that is what this article is about. Why attackers go for your backups first Modern ransomware groups don’t just encrypt blindly. They work systematically: escalate privileges first, then locate the backup infrastructure – backup servers, NAS shares, cloud backups – and eliminate the backups first. On top comes the second extortion stage: data is copied before encryption and used as leverage (double extortion). Your backups only help if they survive the encryption – and having your data leaked changes nothing about your reporting obligations. ...

“Does NIS2 apply to us?” — lately I hear this question from almost every mid-sized company in my region. Understandable: the directive covers far more businesses than its predecessor, and the uncertainty about what exactly applies is huge. The good news: whether you’re probably in scope can be narrowed down with three questions. That’s what this article is about. What NIS2 is — and where Germany stands now The NIS2 Directive ((EU) 2022/2555) is the successor to the first NIS Directive and requires member states to make cybersecurity mandatory for essential and important entities. At its core: organised risk management, reporting of significant incidents, and management responsibility. ...

Why Pandas Instead of Excel Formulas? Excel is ideal for simple tables, but with larger datasets it quickly becomes unwieldy. With Pandas, you can read, analyze, and statistically evaluate Excel files – reproducibly and automatically. Installation pip install pandas openpyxl openpyxl is required for Excel files (.xlsx). Reading Excel Files import pandas as pd # Read Excel file df = pd.read_excel('sales_data.xlsx', sheet_name='Revenue') # First look at the data print(df.head()) print(df.info()) Important parameters: sheet_name='Name' – Select specific worksheet usecols='A:E' – Read only specific columns skiprows=2 – Skip first rows Basic Statistics # Quick overview print(df.describe()) # Individual statistics print(f"Average: ${df['Revenue'].mean():.2f}") print(f"Median: ${df['Revenue'].median():.2f}") print(f"Minimum: ${df['Revenue'].min():.2f}") print(f"Maximum: ${df['Revenue'].max():.2f}") print(f"Total: ${df['Revenue'].sum():.2f}") Output: ...

DNS is one of the most critical infrastructure components on the internet – and simultaneously one of the most vulnerable. DNSSEC (Domain Name System Security Extensions) was developed to close fundamental security gaps in DNS. Despite its importance, DNSSEC is often misunderstood or incorrectly implemented. What is DNSSEC and Why Does it Matter? Classic DNS has a fundamental problem: there’s no way to verify whether a DNS response actually comes from the authoritative nameserver or has been manipulated by an attacker. This enables attacks such as: ...

Saving a Website for Offline Use Using wget, you can download an entire website for offline access with this command: wget -rkpNc -e robots=off http://www.example.com/ Parameters Explained -r: Download pages recursively. -k: Adjust links for local viewing. -p: Fetch all resources (images, scripts). -N: Only download new or modified files. -e robots=off: Ignore robots.txt restrictions. -c: Continue the download if interrupted. With this command, wget reliably saves the entire site for offline use.

cAdvisor on Synology Running cAdvisor in Docker on Synology was a challenge, as it often wouldn’t start despite no changes to the launch options. The issue turned out to be related to the inotify settings. The Problem When running the following command to start cAdvisor: docker run --name=cadvisor \ --volume="/:/rootfs:ro" \ --volume="/var/run:/var/run:ro" \ --volume="/sys:/sys:ro" \ --volume="/var/packages/ContainerManager/var/docker/:/var/lib/docker:ro" \ --security-opt no-new-privileges=true \ --restart=on-failure:5 \ google/cadvisor:latest --docker_only=true cadvisor: image: gcr.io/cadvisor/cadvisor:latest container_name: cadvisor read_only: true security_opt: - no-new-privileges=true command: - "--docker_only=true" volumes: - /:/rootfs:ro - /var/run:/var/run:ro - /sys:/sys:ro - /var/packages/ContainerManager/var/docker/:/var/lib/docker:ro restart: on-failure:5 I encountered the error: ...

This is the first blog post on my new website. I am very excited to share my thoughts and ideas with the world! What I will cover in this blog I plan to write about several topics in this blog, including: Automation Data Science IT Security I hope you are interested in some of these topics and that you will enjoy my future posts. Until next time!