Practical Padding Oracle Attacks on RSA. We introduce RSA giving some simple tools to “play” with it. The only thing we need to recall of RSA is that encryption E(m) and decryption D(y) are defined as exponentiation modulo a big n (at least 1024 bits), respectively using the public e and the private d exponent. Encryption and decryption are such that such that D(E(m)) = m. The OpenSSL toolkit provides very flexible command line tools to perform cryptographic operations. Let us generate a real 1024 bit RSA key-pair using the genrsa command: $ openssl genrsa -out key 1024 Generating RSA private key, 1024 bit long modulus ....++++++ ......++++++ e is 65537 (0x10001) The key has been saved into file named key (option -out). You can see that the encryption exponent e is set to the constant 65537, i.e., 0x10001. . $ openssl pkey -in key -text ... In particular, we see the modulus and the private exponent. . $ echo -ne "\x01" | openssl rsautl -encrypt -inkey key -raw -out enc01 RSA operation error.
. . . $ perl -e 'print "\x00"x127 . Ah! XSLT Server Side Injection Attacks | Context Information Security. Detection and recovery of NSA’s covered up tracks | Fox-IT International blog. Part of the NSA cyber weapon framework DanderSpritz is eventlogedit, a piece of software capable of removing individual lines from Windows Event Log files. Now that this tool is leaked and public, any criminal willing to remove its traces on a hacked computer can use it.
Fox-IT has looked at the software and found a unique way to detect the use of it and to recover the removed event log entries. Introduction A group known as The Shadow Brokers published a collection of software, which allegedly was part of the cyber weapon arsenal of the NSA. Part of the published software was the exploitation framework FuzzBunch and post-exploitation framework DanderSpritz.
DanderSpritz is a full-blown command and control server, or listening post in NSA terms. It can be used to stealthy perform various actions on hacked computers, like finding and exfiltrating data or move laterally through the target network. Figure 1: DanderSpritz with eventlogedit in action eventlogedit eventlogedit in use Like this: OSCP Course & Exam Preparation - Ellingson Mineral.
Full disclosure I am not a penetration tester and I failed my OSCP exam twice before eventually passing on the third attempt. I owned more than 90% of boxes in the labs (including the big three) but when it came to the exam I just kept bombing out. I am hoping something I share here will prevent you from making the same mistakes. Lab Time After years of wanting to do OSCP I got lucky and my employer paid for the full 90 days lab time.
This allowed me to put alot of time into the lab network and pwn all but 5 boxes. I was putting in 4-5 hours a day and a bit more at the weekend but because the labs are so fun it didn’t really feel like work. That’s not to say it was easy at all but the effort I was putting in was being rewarded every time I got mself another root flag. After hearing about the Offensive Security labs for the last few years I got a bit too excited and as soon as I got my VPN access and jumped straight into the lab network without reading any of the documentation. CherryTree. How does Ethereum work, anyway? – Preethi Kasireddy. Now that you’ve gotten the 10,000-foot overview of what a blockchain is, let’s dive deeper into the main components that the Ethereum system is comprised of: accountsstategas and feestransactionsblockstransaction executionminingproof of work One note before getting started: whenever I say “hash” of X, I am referring to the KECCAK-256 hash, which Ethereum uses.
Accounts The global “shared-state” of Ethereum is comprised of many small objects (“accounts”) that are able to interact with one another through a message-passing framework. There are two types of accounts: Externally owned accounts, which are controlled by private keys and have no code associated with them.Contract accounts, which are controlled by their contract code and have code associated with them. Externally owned accounts vs. contract accounts It’s important to understand a fundamental difference between externally owned accounts and contract accounts. Account state World state State trieTransactions trieReceipts trie Blocks Logs.
When you call the number in the popup, they're quick to tell you that you need a new modem, which in my case is not true. I later verified with level-2 support that my modem is pefectly fine and I don't need to upgrade. As deceptive as that is however, my major complaint is that Comcast is intercepting web pages and then altering them by filling them with hundreds of lines of code. Comcast has my phone office number, my cell for texts, my email, and my home address, yet they choose to molest my requested web pages by injecting hundreds of lines of code. Titre. Asintsov: Data exfiltration with Metasploit: meterpreter DNS tunnel. Meterpreter is a well-known Metasploit remote agent for pentester's needs. This multi-staged payload is a good, flexible and easy-to-use platform that allows pentesters to have remote control over pwnedpenetrated host. Currently it supports following "network" transports:Binding TCP portReverse connection over TCP/IPReverse connection over HTTP Last year we, at defcon-russia, have started a fun opensource community project regarding implementing another network transport for meterpreter: reverse DNS (tunnel).
Last week we also have presented it at ZeroNights. In that blog-post I want to share results of this work, future plans and main benefits and features. Transport design and components Our current "pre-release" is only supports windows platforms (both, x64/x86) and consists of following main components:DNS MSF Bridge (as intermediate server)Meterpreter DNS transportMSF stager payloads (shellcodes, x64/x86) The DNS MSF Bridge is a Python script which is used as DNS server. HowTo . . Nnamon/linux-exploitation-course: A Course on Intermediate Level Linux Exploitation. Neat tricks to bypass CSRF-protection. The Infamous Windows “Hello World” Program. Charles Petzold on writing books, reading books, and exercising the internal UTM December 8, 2014New York, N.Y. A recent blog post by consultant John Cook reminded everybody about the infamous "Hello World" programs in the early chapters of the first five editions of Programming Windows: “Hello world” is the hard part Following a little discussion on my Facebook page initiated by my Xamarin colleague and old friend Larry O'Brien, I began to realize that some people believe that I invented the excessively overlong Windows "Hello World" program.
I'm afraid I did not. I learned Windows programming from documents included with the Windows 1.0 beta and release Software Development Kits. I no longer have the 5" floppies that contained the sample code, but I do still have the binder with the Programming Guide and the printed listings. Here is the listing of the HELLO.C file from that Windows Programming Guide, patched together from scans of four pages: I tried a bunch of other simplifications.
If (! Reverse engineering the Intel FSP… a primer guide! Recently, I’ve finished reverse engineering the Intel FSP-S “entry” code, that is from the entry point (FspSiliconInit) all the way to the end of the function and all the subfunctions that it calls. This is only some initial foray into reverse engineering the FSP as a whole, but reverse engineering is something that takes a lot of time and effort. Today’s blog post is here to illustrate that, and to lay the foundations for understanding what I’ve done with the FSP code (in a future blog post). Over the years, many people asked me to teach them what I do, or to explain to them how to reverse engineer assembly code in general. Sometimes I hear the infamous “How hard can it be?” Catchphrase. Last week someone I was discussing with thought that the assembly language is just like a regular programming language, but in binary form—it’s easy to make that mistake if you’ve never seen what assembly is or looks like.
The stack First I’ll explain what “the stack” is. The registers The instructions. Securing an ASP.NET Core Web API 2 using Azure AD B2C – Sara Ford's Blog. In a previous post you saw how to secure and call an ASP.NET Web API using Azure AD B2C. Today’s post is how to secure an ASP.NET Core Web API 2. This blog post walks you through the steps from File – New – Project to using Postman to test your API with an access token. Here’s the official ASP.NET Core sample Create the project Since this is my first ASP.NET Core project, I spent some time playing with the getting started first-web-api tutorials. File – New – Project – .NET Core – ASP.NET Core Web ApplicationI called mine HelloCoreAPI, because in my previous post I had registered a HelloAPI and you need to use an unique App ID URISelect Web API Make sure ASP.NET Core 2.0 is selected (I’m using VS 2017 so it’s the default)Make sure No Authentication is set And hit F5 just to make sure things are working.
Create the /hello endpoint I spent some time exploring the documentation on ASP.NET Core routing. I’ve setup my route to look like Hit F5 and see “Hello there!” Enable https Setup Middleware 2. Bypassing SAML 2.0 SSO with XML Signature Attacks • Aura Information Security Research Blog. We’ve recently noticed a trend with a lot of New Zealand sites wanting to implement Single Sign-On (SSO) to combat the proliferation of passwords, including many government services. The most prevalent standard for doing this, providing interoperability between many vendors’ frameworks and multiple languages, is SAML 2.0. The usual mechanism for this passes the SAML response certifying the user’s identity through the web browser, using a signature to prevent tampering.
Unfortunately, many SAML consumers don’t validate responses properly, allowing attacks up to and including full authentication bypass. When signing in to a site with SAML 2.0, there are three parties involved - the Service Provider (‘SP’, the web application we want to access), the Principal (the user logging in) and the Identity Provider (‘IdP’, the authority). We do this by having the Service Provider redirect our user to the Identity Provider with a SAML request. HTTP Redirect Binding. Is a Signature Required?
KRACK - Casser le WPA2 - hackndo. Cet article est une revue de l’attaque KRACK - Key Reinstallation Attack présentée par Mathy Vanhoef dans son papier. Avec cette attaque, il est possible de casser le protocole WPA2 en interceptant et décryptant des communications sans être authentifié sur le réseau. Ici, je tente de détailler le plus clairement possible le fonctionnement de cette attaque en rappelant quelques notions autour desquelles gravite l’attaque, comme le problème cryptographique qui entre en jeu, ou le 4 way handshake utilisé dans le protocole WPA2. J’ai commencé un PoC de l’attaque sur Github qui marche de temps en temps mais qui reste très instable. Si vous vous sentez de le regarder, le comprendre, et l’améliorer, n’hésitez pas !
Problème cryptographique Cette attaque profite d’une erreur d’implémentation dans un protocole afin de résinstaller une clé cryptographique déjà utilisée tout en réinitialisant des paramètres censés être uniques. Exemple schématique représentant le chiffrement CCMP: donc 4 way handshake. Image Steganography: Hiding text in images using PHP - The Debuggers. Steganography is the art and science of writing hidden message in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message.
Image Steganography is the technique of hiding the data within the image in such a way that prevents the unintended user from the detection of the hidden messages or data. Related Theory: Images are made up small units of dots called as pixels. Each pixel is represented as 3 bytes : one for Red, one for Green and one for Blue. The composition of these three colors determines the actual color that pixel shows. Red : Binary: 11001001 Decimal: 201 Green: Binary: 11111000 Blue: Binary: 00000011 Decimal: 3 This composition gives rise to orange color. The basic idea in Image Steganography lies in the fact that a change in the Least Significant Bit (LSB) is not detected by human eye. In this example, we change the LSB of Blue component only. Suppose we want to hide 1101 in the image.
First we get RGB value of each pixel in the image. Understanding Ethereum Smart Contracts - Gjermund Bjaanes. You might have heard the term “smart contract,” and you might even know that they are “code” you can run on a blockchain. But how can you run code on a blockchain? It’s not the easiest concept to wrap your head around. This post explains how smart contracts work on the Ethereum Blockchain. Basic understanding of programming will help as this post contains some code - although the examples a simple. Some technical details in this post are slightly simplified for the sake of clarity, but the concepts are valid. Without going into too much detail, the central concept of Blockchain technology is a distributed ledger. This special database is just a list of transactions.
Traditionally, trust between parties has been solved using middlemen, third parties. With blockchain, this need is eliminated because you can instead put your trust in a network where the want to cheat is removed by strong incentives (in short: it’s much more profitable to stay within the rules). A user account is just. Advbof. Inject All the Things - Shut Up and Hack. Well, its 2017 and I’m writing about DLL injection. It could be worse. DLL injection is a technique used by legitimate software to add/extend functionality to other programs, debugging, or reverse engineering. It is also commonly used by malware in a multitude of ways. This means that from a security perspective, it’s imperative to know how DLL injection works.
I wrote most of the code of this small project, called ‘injectAllTheThings’, a while ago when I started developing custom tools for Red Team engagements (in order to emulate different types of threat actors). If you want to see some examples of threat actors using DLL injection have a look here. You may also find this project useful if you want to learn about DLL injection.
Below is the output of the tool, showing all the options and techniques implemented. According to @SubTee, DLL injection is lame. You can load DLLs with signed Microsoft binaries indeed, but you won’t attach to a certain process to mess with its memory. Code. Découvrez l'attaque "Return Oriented Programming" ! • Articles • Zeste de Savoir. Après une longue période de calme, on attaque le sixième article d'une série sur l'emploi du langage binaire sur les systèmes d'exploitation, de la rétro-ingénierie à l'écriture d'un « Hello world » en langage d'assemblage tout en passant par des techniques d'exploitation de vulnérabilité système. Aujourd'hui, je vais vous parler d'une technique intitulée Return Oriented Programming qu'on abrège communément ROP. Contrairement à un traditionnel stack-based overflow, le ROP a été imaginé et baptisé ainsi pour contourner les mécanismes de protection qui avaient été mis en place pour empêcher les exploitations basiques de type stack-based overflow où, comme je vous le montrais dans mon article précédent, on plaçait dans la pile d'exécution un shellcode.
En effet, avec le temps, les systèmes d'exploitation se sont munis des protections suivantes : Eh bien figurez-vous que le ROP contourne ces deux protections à la fois. Et je vais vous le prouver en trois parties ! Le programme La vulnérabilité. Reversing DirtyC0W - Life At Tetrane. XSLT Server Side Injection Attacks | Context Information Security. Reverse Engineering The MacOS AirPlayUIAgent - Part 001 — rotlogix. Cours n°16. Intro to Analyze NFC Payment Methods & Contactless Cards – Salvador Mendoza Blog. Learn from your attackers - SSH HoneyPot. How does blockchain really work? I built an app to show you. A journey into Radare 2 – Part 2: Exploitation – Megabeets. Shellphish/how2heap: A repository for learning various heap exploitation techniques.
Eset gazer. Lecture Videos | Computer Systems Security | Electrical Engineering and Computer Science | MIT OpenCourseWare. Lecture Notes | Computer Systems Security | Electrical Engineering and Computer Science | MIT OpenCourseWare. T1106220. Petit Manuel du ROP à l'usage des débutants - Daily Security. Google Cloud Platform Blog: Introducing App Engine firewall, an easy way to control access to your app. Analysing a recent Poison Ivy sample. Linux Network Commands - DZone DevOps. DOMAngularSandboxEscapes. Restic cryptography. Cisco's Talos Intelligence Group Blog: Booters with Chinese Characteristics: The Rise of Chinese Online DDoS Platforms.
Android NDK - Reverse engineering d'une application ARM - NES. TR17 ME11 Static. Mining Bitcoin with pencil and paper. b81efa3a4c5826fa441852bd63a402c6. 806. 1708.06733v1. Exploiting JSON Cross Site Request Forgery (CSRF) using Flash | Geekboy | Security Researcher.
Scan multiple organizations with Shodan and Golang. Bug Bounty example. Guide to Ransomware Prevention & Detection. Exploiting Script Injection Flaws in ReactJS Apps – DailyJS – Medium. How to Embed a Metasploit Payload in an Original .Apk File | Part 2 – Do It Manually « Null Byte :: WonderHowTo. Hybrid focused crawling on the Surface and the Dark Web | EURASIP Journal on Information Security | Full Text.
CoMisSion – Whitebox CMS analysis – Intrinsec. Build Your Own Linux: Presented by Linux Academy. Technique du Canari : Bypass - hackndo. MJS 053 Weichselbaum CSP. API security testing - tips to prevent getting pwned : Assertible. WHID Injector: an USB-Rubberducky/BadUSB on Steroids: Weaponize a Mouse with WHID Injector for Fun & W00t. Let's Learn: How to Obtain Cerber (CRBR) Ransomware Configuration | Vitali Kremez | Ethical Hacker | Reverse Engineer. Make your own USB Rubber Ducky using a normal USB stick.
The Complete Guide To Switching From HTTP To HTTPS. DNS Sinkhole setup. Reverse Engineering an Eclipse Plugin – Learning Security. Intro to Linux Forensics | Count Upon Security. Dumping the GBA BIOS. Awesome-Fuzzing/README.md at master · secfigo/Awesome-Fuzzing. Griffin asplos17. Hack-with-Github/Awesome-Hacking: A collection of various awesome lists for hackers, pentesters and security researchers. Hackers-arise. Java Deserialization Exploit Resulting RCE on Thick Client Penetration Testing. How to develop your own Boot Loader - CodeProject. Open Analysis Live: Viewer Submission - Decoding Malicious .vbs Scripts. Open Analysis Live: Reverse Engineering a DGA (Domain Generation Algorithm)