Sysadmins of the North (Page 9)

Technical SysOps blog, where topics include Sysadmin, DevOps, computers, servers, web, MySQL, database, virtualization, optimization and security

PowerShell blacklist check script: find an IP address' blacklist status & reputation

Here's a blacklist check script written in PowerShell. You can use this to lookup an IP address in various blacklists (DNSBL, RBL). Such a check is a great indicator for an IP address' reputation. Basically this PowerShell blacklist checker is a port of my Bash script to check an IP address blacklist status in Linux.

Read more...

Ghost on IIS with HTTPS, how to resolve a "Too many redirects" error

When you use iisnode to host the Node.js blogging software Ghost on your IIS web server you may encounter a \"Too many redirects\" error while setting up and TLS/SSL certificate for your site. Here is the solution.

AppCmd introduction and examples

The `AppCmd.exe` command is your one-stop-shop for administering Windows Server IIS web servers. In combination with WinRM it's your Swiss Army knife for your daily routine. This post introduces appcmd and provides you with a lot of helpful appcmd examples.

Get current number of FTP client connections (NonAnonymous) with PowerShell and Get-Counter

Ever wanted to know the current number of active FTP client connections on your Windows Server IIS FTP Service? You can get this statistic using PowerShell, the `Get-Counter` cmdlet and the Microsoft FTP Service Current NonAnonymous Users performance counter.

Simple PowerShell introduction for Windows Server administration, automation and scripting

Windows PowerShell is an important tool in Windows Server for administrators. You can use PowerShell for Windows Server administration, software installation, automation, and shell/command-prompt scripting.

Binary webshell through OPcache in PHP 7

GoSecure wrote up a new PHP exploitation technique using the default OPcache engine from PHP 7. Using this attack vector, it's possible to bypass certain hardening techniques that disallow the file write access in the web directory. This could be used by an attacker to execute his own malicious code in a hardened environment.

Read more...

Windows Update error 0xc1420127 and 0xc190010b when upgrading Windows 8.1 to Windows 10

After downloading the Windows 10 update through Windows Update, Windows Update returned errors `0xc1420127` and `0xc190010b`, even after using the Windows 10 media creation tool

How to install Microsoft's SQL Server Driver for PHP

This post walks you through the steps necessary to install the SQL Server driver and SQLSRV extension for PHP 7+, on Windows Server IIS of course.

Optimize WordPress MySQL tables through Cron, behind the scenes

To regularly optimize my WordPress database tables, I created a small plugin that utilizes the WordPress Cron feature. This comes in handy to perform database optimization for WordPress on a regular basis, without forgetting about it. Just activate and enjoy. And here is the plugin code.

HackRepair.com's Bad Bots .htaccess in web.config for IIS

Learn to protect your WordPress website with this web.config file

IIS URL Rewrite "Rewrite Module error: Expression contains a repeat expression"

The other day, I had to migrate a website from a Linux / Apache web server to Windows Server IIS. Yes, that type of migration happens too, sometimes. The website in question had a lot of sub domains, all pointing to folders within the web root using that same name: foobar.example.com would redirect (rewrite) to www.example.com/foobar.

Cracking PHP rand()

This is a very interesting read about how PHP rand() works, and how to attack & crack it...

Recursive scp and symlinks

TL;DR, when using recursive scp, symbolic links aren't preserved and are copied as if they are normal directories. So you have to look for another solution to recursively transfer symlinks over ssh. Use Tar over ssh!

Deny vulnerable WordPress plugins using Windows Server File Server Resource Manager's File Screens

Using Windows Server File Server Resource Manager (FSRM) File Screens you can block vulnerable WordPress plugins from being uploaded to your [IIS](/tags/iis/) web server. In the following example, you'll learn how to block WP DB Backup plugin system-wide on Windows Server, read on...

Install Varnish Cache on CentOS 6.7

In this article I'll show you how to install Varnish Cache on CentOS, version 6.7 in this case. Varnish is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Because Varnish Cache is really, really fast, web applications like WordPress, Drupal and Joomla can greatly benefit from Varnish Cache.

Read more...