end-to-end cryptography

2 Articles

This Week In Security: Open Source C2, Raptor Trains, And End To End Encryption

September 20, 2024 by 14 Comments

Open Source has sort of eaten everything in software these days. And that includes malware, apparently, with open source Command and Control (C2) frameworks like Sliver and Havoc gaining traction. And of course, this oddball intersection of Open Source and security has intrigued at least one security researcher who has found some interesting vulnerabilities.

Before we dive into what was found, you may wonder why open source malware tools exist. First off, trustworthy C2 servers are quite useful for researchers, who need access to such tools for testing. Then there is Red Teaming, where a security professional launches a mock attack against a target to test its defenses. A C2 is often useful for education and hobby level work, and then there are the true criminals that do use these Open Source tools. It takes all types.

A C2 system consists of an agent installed on compromised systems, usually aiming for stealth. These agents connect to a central server, sending information and then executing any instructions given. And finally there’s a client, which is often just a web interface or even a command line interface.

Now what sort of fun is possible in these C2 systems? Up first is Sliver, written in Go, with a retro command line interface. Sliver supports launching Metasploit on compromised hosts. Turns out, it accidentally supported running Metasploit modules against the server’s OS itself, leading to an easy remote shell from an authenticated controller account.

Havoc has a fancy user interface for the clients, and also a command injection flaw. A service name field gets used to generate a shell command, so you’re only a simple escape away from running commands. That’s not quite as useful as the API that failed open when a bad username/password was given. Oops. Continue reading “This Week In Security: Open Source C2, Raptor Trains, And End To End Encryption” →

Simple Encryption You Can Do On Paper

May 12, 2021 by 73 Comments

It’s a concern for Europeans as it is for people elsewhere in the world: there have been suggestions among governments to either outlaw, curtail, or backdoor strong end-to-end encryption. There are many arguments against ruining encryption, but the strongest among them is that encryption can be simple enough to implement that a high-school student can understand its operation, and almost any coder can write something that does it in some form, so to ban it will have no effect on restricting its use among anyone who wants it badly enough to put in the effort to roll their own.

With that in mind, we’re going to have a look at the most basic ciphers, the kind you could put together yourself on paper if you need to.

Continue reading “Simple Encryption You Can Do On Paper” →