---
layout: default
permalink: /RE101/section2/
title: Malware Techniques
---
[Go Back to Reverse Engineering Malware 101](https://securedorg.github.io/RE101/)

# Section 2: Malware Techniques #

## Typical Attack Flow ##

| Perimeter Recon | Infiltrate | Internal Recon | Entrench | Exfiltrate | Purge |
| ------------ |:------------:|:------------:|:------------:|:------------:|:------------:|
| ![alt text](https://securedorg.github.io/images/rightarrow.png) | ![alt text](https://securedorg.github.io/images/rightarrow.png) | ![alt text](https://securedorg.github.io/images/rightarrow.png) | ![alt text](https://securedorg.github.io/images/rightarrow.png) | ![alt text](https://securedorg.github.io/images/rightarrow.png) | ![alt text](https://securedorg.github.io/images/rightarrow.png) |

## Techniques Overview ##
* [Compression](#compression)
* [Obfuscation](#obfuscation)
* [Persistence](#persistence)
* [Privilege Escalation](#privilege-escalation)
* [Defense Evasion](#defense-evasion)
* [Credential Theft](#credential-theft)
* [Reconnaissance](#recon)
* [Lateral Movement](#lateral-movement)
* [Execution](#execution)
* [Collection](#collection)
* [Exfiltration](#exfiltration)
* [Command and Control](#command-and-control)

## Compression

* Combining the compressed data with decompression code into a single executable
* Runtime packers
* Self extractive archives
* List of packers
  * [Themida](http://www.oreans.com/themida.php)
  * [Armadillo](http://www.siliconrealms.com/armadillo.php)
  * [ASPack](http://www.aspack.com/aspack.html)
  * [ASPR (ASProtect)](http://www.aspack.com/asprotect32.html)
  * [BoxedApp Packer](http://www.boxedapp.com/boxedapppacker)
  * [CExe](http://www.scottlu.com/Content/CExe.html)
  * [dotBundle](http://www.dotbundle.com)
  * [Enigma Protector](http://www.enigmaprotector.com)
  * [EXE Bundle](http://www.webtoolmaster.com/exebundle.htm)
  * [EXE Stealth](http://www.webtoolmaster.com/exestealth.htm)
  * [eXPressor](http://www.cgsoftlabs.ro/express.html)
  * [FSG](http://xtreeme.prv.pl/)
  * [kkrunchy](http://www.farbrausch.de/~fg/kkrunchy/)
  * [MEW](https://web.archive.org/web/20070831063728/http://northfox.uw.hu/index.php?lang=eng&id=dev)
  * [MPRESS](http://www.matcode.com/mpress.htm)
  * [Obsidium](http://www.obsidium.de)
  * [PESpin](http://pespin.w.interia.pl)
  * [Petite](http://www.un4seen.com/petite)
  * [RLPack Basic](http://www.softpedia.com/get/Programming/Packers-Crypters-Protectors/RLPack-Basic-Edition.shtml)
  * [Smart Packer Pro](http://www.smartpacker.nl)
  * [Themida](http://www.oreans.com/themida.php)
  * [UPX](https://upx.github.io/)
  * [VMProtect](http://vmpsoft.com/products/vmprotect)
  * [XComp/XPack](http://soft-lab.de/JoKo)
  
  <center>[Top^](#techniques-overview)</center>
  
## Obfuscation

* Deliberate act of creating obfuscated code that is difficult for humans to understand
* Plain text strings will appear as base64 or Xor
* Malicious behavior will include junk functions or routines that do nothing to throw off the reverser.
    * Control-Flow Flattening
    * String Encryption
    
![alt text](https://securedorg.github.io/images/CodeObfuscation.gif "CodeObfuscation")

## Persistence 

* Once malware gains access to a system, it often looks to be there for a long time. 
* If the persistence mechanism is unique enough, it can even serve as a great way to identify a given piece of malware.

![alt text](https://securedorg.github.io/images/Persistence.png "Persistence")
 
## Privilege Escalation

* Exploiting a bug, design flaw or configuration oversight in an operating system or software application to gain elevated access to resources that are normally protected from an application or user.
* Common Techniques:
  * Dll Search Order Hijacking
  * Dll injection
  * Exploiting a vulnerability
    * BufferOverflow
    * StackOverflow
    * Headspray
    * Return Orientated Programming (ROP)
  * Credential Theft
  * UAC Bypasses

Example: Dll Search Order Hijacking
![alt text](https://securedorg.github.io/images/DLLload.gif "Dll loading")

## Defense Evasion   
* Evading detection or avoiding defenses.
* Common Techniques:
  * Killing AV
  * Deleting itself after a run
  * Timebombs/Timestomping
  * Stolen Certificates
  * Dll Side Loading
  * Masquerading
  * Process Hallowing

## Credential Theft

* Going after password storage
* Keylogging passwords
* Screenshots

Example: Mimikatz credential theft
![alt text](https://securedorg.github.io/images/mimikatzElevate.png "Mimkatz Elevating")

## Reconnaissance   

* Gain knowledge about the system and internal network.

## Lateral Movement   

* Enable an adversary to access and control remote systems on a network and could  

## Execution

* Techniques that result in execution of adversary-controlled code on a local or remote system
* scripts
* post-exploitation

## Collection

* Identify and gather information, such as sensitive files, from a target network prior to exfiltration

## Exfiltration

* Removing files and information

## Command and Control

* Communicate with systems under their control 

[x86 Assembly <- Back](https://securedorg.github.io/RE101/section1.3) | [Next -> Section 3](https://securedorg.github.io/RE101/section3)