malware-persistence - Collection of malware persistence and hunting info

项目说明

An awesome list with only the links is found on awesome-malware-persistence.

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Collection of malware persistence information

This repository collects currently scattered information regarding the
detection, the response and the log collection of malware persistence
mechanisms.

In short, we look for one of the things which is so common between different
malware families: the ability to persist on a target host. Also malware
associated with the misleading term "fileless" often persists on the target
too, though not through regular files on the file system but through changes
in configuration files like Windows Registry or cron jobs.

Unfortunately, many malware blog posts include all the IP and hash
information but only a few highlight the persistence mechanism from an attack,
despite that it's one of the more static and more difficult to change
information from an attacker's perspecti the persistence mechanism to
hunt for malware is more robust than the more frequently changed IP addresses
or hashes.

If you're only looking for an o about persistence techniques and some
links to useful resources then see O of commonly used persistence mechanisms and links and resources for detection. See section tools for some well-known persistence collection tools.

This repository is regularly updated with new detection resources and tools.
If you ha then pull requests are more then welcome!

<!-- GFM -->

* Why bothering with malware persistence?
* Detection
* Approach
* O of commonly used persistence mechanisms
* Linux
* MacOS
* Windows
* Cloud
* All OSes and de specific changes
* O of difficult to detect persistence mechanisms
* Persistence through UEFI malware and bootkits
* Links and resources for detection
* Examples
* Detection E
* Testing
* Response
* Pre
* Tools
* Linux
* MacOS
* Windows
* Acknowledgement

<!-- -->

Why bothering with malware persistence?

If you are an incident responder and have to analyze compromised hosts, do a
generic compromise assessment or if you do threat hunting acti in your
infrastructure, then you should get into the topic of persistence mechanisms as
one way to detect known or unknown malware. It's one of the pieces for looking
for during IR acti.

Let's start with the persistence
technique description used by
MITRE:
> The ad is trying to maintain their foothold.
>
> Persistence consists of techniques that ad use to keep
> access to systems across restarts, changed credentials, and other
> interruptions that could cut off their access. Techniques used for
> persistence include any access, action, or configuration changes that
> let them maintain their foothold on systems, such as replacing or
> hijacking legitimate code or adding startup code.

One thing in common between different malware families is that they
(mostly) try to persist on the target host. Malware associated with the
misleading term "fileless" often persists on the target too, though not through
regular files on the file system but through changes in configuration files
like Windows Registry or cron jobs.

Why use the word _mostly_ abo there is rare malware which omit
setting persistence mechanism on the 's host itself but reinfect the host
after reboot from another system (e.g. DC, where the system is running longtime
on which no persistence is needed at all).

This gold mine of malware persistence information is a fraction of what other
log sources produce. Tens to hundreds of events depending of what you looking
for thousand to ten thousands of entries for process information.
Therefore, the analysis of these events reduce the time and the effort
compared to other log sources considerably. The signal to noise ratio is also
much lower.

So, by becoming and being a persistent persistence hunter, you can make use of
this treasury. Though not that kind of persistence hunting described in
Wikipedia...
> Persistence hunting (sometimes called endurance hunting) is a hunting
> technique in which hunters, who may be slower than their prey o
> distances, use a combination of running, walking, and tracking to pursue prey
> until it is exhausted. A persistence hunter must be able to run a long
> distance over an extended period of time.

Detection

While there are many ways how malware can persist on a host, malware authors
rely mostly on a handful of techniques. Beside these often used techniques
some malware families and more targeted attacks use more ad mechanisms
to stay hidden on the system.

Keep in mind that for some persistence techniques escalated pri are
required and therefore malware running under normal users (and pri
escalation left out of consideration) can only set "user mode" persistence. So
if the user on the infected host only use a normal user account then first
focus on the user le and secondly look for system level
techniques.

Approach

The analysis process could invol steps, as with other incident
response and threat hunting procedures:
1. Collect the persistence mechanisms using single commands for specific
techniques (see links and resources for
detection) or use tools for collection
of a bunch of them at the same time, see tools.
2. Analyse the command, file hash, file signer and file path information and
enrich the information with more information from external services (AV
detection rate, correlation with other files, reputation, signer
information, known-bad hash check).
3. If the output doesn't help, check the information against other clients in your
infrastructure: Is this entry found on other hosts too?
4. Look for anomalies, e.g. an exe file in startup folder where normally only
.lnk files should be placed is suspicious or look for IP addresses or web
request in cronjobs. See the links below for detection ideas.
5. In the process of the analysis it is important to note too what is NOT found
(e of absence) and not only what is found, e.g. no cron jobs were
found at all.

O of commonly used persistence mechanisms

The used techniques from user land persistence mechanisms, to system
le, from hiding behind common binary names, to putting malware
at unusual but lesser known places. Sometimes only a proxy or other network
configuration (i.a. DNS settings) changes were found after infection. Retefe used
the latter.

Use the information from section links and resources for
detection for specific information for
these techniques.

#### Linux
* Often used techniques: startup, rc and init scripts, cron jobs, shell scripts, shell profiles.
* In-depth analysis should further include less frequently used techniques:
malicious libraries, loadable kernal modules (LKM), binary replacements or network scripts.

#### MacOS
* Often used techniques: launch daemons and agents, startup items, shell scripts, shell profiles.
* In-depth analysis should further include less frequently used techniques: Dylib hijacking.

#### Windows
* Often used techniques: registry run keys, scheduled tasks, services, startup folder.
* In-depth analysis should further include less frequently used techniques:
e.g. file handler hijacking (check both HKLM and HKCU), WMI implants, DLL side loading, malicious
drivers, LNK files, sneaky way to get persistence through RDP
connections on Windows is the use of image hijacks, sometimes known as
"sticky keys hijacking" or known as technique "Accessibility Features" in
the ATT&CK Matrix, COM Hijacking (check both HKLM and HKCU).

#### Cloud
* Shadow Linking: The Persistence of SaaS Identity Threat
* Persisting on Entra ID applications and User Managed Identities with Federated Credentials
* Mapping storage to external storage pro.
* AWSDoor: Persistence on AWS - Access persistence tool for AWS. The corresponding article describes the techniques ad can use to hide themsel a cloud en and its AWSDoor implementation to simplify and automate the deployment of persistence techniques in AWS en.

#### All OSes and de specific changes
* Proxy and other network configuration changes, backdoor accounts
and shortcut modifications.
* De workstations: e.g. modified IDE software and git hook scripts.

O of difficult to detect persistence mechanisms

* Malware which omit setting persistence at all on the 's host but
reinfect the host after reboot from another system, e.g. from a DC (a
system which is running long time and no persistence is needed at all).
* Persistence, e.g. through registry run keys, is only set shortly before
the shutdown command (shutdown command is hooked). Used in Dridex malware
in the past. Cool thing, if you knew that, you could cold boot the
computer and "deactivate" Dridex.
* Abuse of hooked file handler.
* DLL side loading (file can be anywhere on the system).
* Legitimate binary replacement.
* Firmware changes pre getting rid of malware by normal patching. Example.
* Database triggers pre getting rid of malicious access by restoring a backup: The Attack : Database Triggers as Persistence Mechanisms.

Persistence through UEFI malware and bootkits

* (UEFI) firmware malware, bootkits or modified kernel images. These can be
detected by checking the signed binaries from the client (Secure Boot). See
MoonBounce: the dark side of UEFI
firmware
for a in depth write up about one particular UEFI bootkit.
* _Analysis has shown that a single component within the inspected
firmware’s image was modified by attackers in a way that allowed them to
intercept the original execution flow of the machine’s boot sequence and
introduce a sophisticated infection chain._
* See section "Re the current state of the art in persistent
attacks" for a brief history of UEFI malware. From this section: _In the
last year, there have been several public accounts on the ongoing trend of
UEFI threats. Notable examples include the UEFI bootkit used as part of
the FinSpy sur toolset that we reported on, the work of our
colleagues from ESET on the ESPectre bootkit, and a little-known threat
activity that was discovered within go organisations in the Middle
East, using a UEFI bootkit of its own [...] MoonBounce is notable for
being the third publicly re case of an implant from the latter class
of firmware-based rootkits. Previous cases included LoJax and
MosaicRegressor, which we reported on during October 2020._

Links and resources for detection

The following resources cover a lot of persistence techniques and more
information on how to detect these specific mechanisms.

#### MITRE ATT&CK tactic "TA0003 - Persistence"

One of the most comprehensi of persistence techniques is the list
found in MITRE ATT&CK tactic "TA0003 - Persistence".
Besides a description, different mitigations and a detection section is provided. Furthermore,
the in actors using these techniques are listed on the page.

URL:

#### Hexacorn's blog persistence category

A second gold mine for persistence information is found on Hexacorn's
blog where
regularly and since long time new techniques and blog posts about persistence
mechanisms are published, crazy stuff. You'll also find there the legendary
series "Beyond good ol’ Run key".

URL:

#### thee's series "Beyond the good ol' LaunchAgents"

Series about persistence on macOS beyond just the LaunchDaemons or
LaunchAgents directories. In the introduction
it's also refered to Pasquale Stirparo's posts (here and here) with the name
*Beyond the good ol' LaunchAgent* from 2018.

URL:

#### Forensic artifact repository

The forensic artifact
repository covers different
artifacts regarding persistence for different OSes. See yaml files for MacOS,
Linux and Windows in the
data
directory.

URL:

#### Sigma rules

Sigma rules also include
rules regarding persistence. Search for persistence rules in Sigma
repository
or use the filter options of Sigma for either MITRE ATT&CK persistence
category itself or for one specific technique:

URL:

#### Autoruns

You can learn which Windows persistence mechanisms are possible by looking at
the output of Autoruns on your own client (see also tools). In the
output you see the categories and the different locations where things were
found. To see which entries Autoruns scans at all, you can start a
disassembler and look at the strings found in the binary, this covers only a
subset.

URL:

Another way to find Windows persistence information is to look at the PowerShell implementation of Autoruns, where the
locations are found in the source code. Bonus: A history of the covered persistence locations for each is found there too, which is awesome!

URL:

#### KnockKnock

For macOS there's the KnockKnock persistence tool to look for persistence mechanisms: Specific persistence locations are found in the plugins folder, e.g. LaunchItems or StartupScripts.

#### PoisonApple

PoisonApple is a command-line tool to perform persistence mechanism techniques on macOS. This tool was designed to be used by threat hunters for cyber threat emulation purposes. Learn about macOS persistence techniques by looking at the source code of PoisonApple.

#### PANIX

Panix- Persistence Against *NIX - Features is a highly customizable Linux persistence tool and includes persistence techniques.

#### blog posts

blog posts write about persistence mechanisms, some specific for one
technique, others for a broader set of techniques. Here are some for the past
years as an inspiration what to look for.

See How malware persists on macOS for macOS persistence locations, General persistence mechanisms: Common malware persistence mechanisms, Malware persistence techniques, WMI: Detecting & Removing an Attacker’s WMI Persistence, Winlogon: Windows Persistence using WinLogon, Kovter: Untangling Kovter’s persistence methods, Threat Spotlight: Kovter Malware Fileless Persistence Mechanism, GlobalFlags in Image File Execution Hijacks: Persistence using GlobalFlags in Image File Execution Options – Hidden from Autoruns.exe, Bootloader persistence: Unco a MyKings With Bootloader Persistence Detection and Response, COM hijacking / CLSID hijacking: gdatasoftware writeup from 2014 or pentestlab writeup from 2020 or Enigma0x3 / Matt Nelson's writeup from 2016 abusing com hijacking in combination with scheduled tasks, Linux cron: Linux Malware Persistence with Cron, Microsoft Exchange and Outlook: Hunting for persistence Exchange Server or Outlook, Shadow Linking: The Persistence of SaaS Identity Threat, Linux Detection Engineering - A primer on persistence mechanisms, Linux LKM Persistence - Rootkit le Linux loadable kernel module (LKM), AWSDoor: Persistence on AWS, Access persistence for AWS.

Examples

#### MITRE ATT&CK persistence technique called Local Job Scheduling

In the list from the tactic's
page, we can na to the
technique itself, namely T1168 - local job
scheduling and get the
description and the needed information about the in tools and files:

> On Linux and macOS systems, multiple methods are supported for creating pre-scheduled and periodic background jobs: cron, at, and launchd.
>
> [...]
>
> System-wide cron jobs are installed by modifying /etc/crontab file, /etc/cron.d/ directory or other locations supported by the Cron daemon, while per-user cron jobs are installed using crontab with specifically formatted crontab files.

Further below the detection ideas are provided. Besides the process monitoring
we can spot malicious jobs by comparing the cron files and commands against other hosts or
just search for unusual commands.

A writeup on bleepingcomputer regarding a cryptominer on Linux shows an example of such a cron entry. IP changes but the persistence technique using the crontab and a web request stays. So hunt them down!

#### (Ab)use of Rundll32

A second example is the (ab)use of rundll32.exe to load a library through
registery keys or other means (T1085 - Rundll32).
Ursnif is one of the malware families which use a specific rundll32 command
line since long time. Therefore, searching for registry keys containing
"rundll32" and "DllRegisterServer" in the command line would catch it or just
use "rundll32" as a more generic search pattern.

Example taken from Trendmicro's URSNIF threat encyclopedia

#### File handler manipulation

Sneaky persistence through manipulation of exefile file handler. MITRE ATT&CK T1546.001 - Event Triggered Execution: Change Default File Association. Lokibot sample from Nov 2021. Check both HKLM and HKCU.

and malware was dropped to C:\Windows\s.com.

Detection E

Malware authors abuse different techniques to hide their malware persistence
or make the detection more difficult:
* Rootkits hide files or hook registry queries
* Use similar or typosquatted names to OS default binary names
* Hidding entries by abusing program bugs, like the one with the null byte in registry keys which results in error while collection or just missing entries in the output of tools
* Abusing ADS (alternate data streams) in windows
* Using DLL side-loading for well-known binaries
* Using signed binaries which then gets filtered out (depending on the analysis)
* Hidden services when special permissions were set at service creation. Seen in section _Installation stealth and persistence_ in Talos' blog post Threat hunting in large datasets by clustering security events. This blog post references another one from SANS, Red Team Tactics: Hiding Windows Services.
* _In the following steps, the script deletes PowerShell logs and registers the final payload as a Windows service using a long command line with some strange permission settings. A quick Google search reveals that these are used to make the service hidden and unremovable using the regular Windows administration tools, without some additional actions. [Talos]_
* _A little known feature of Windows allows the red team or an attacker to hide services from view, creating an opportunity to evade detection from common host-based threat hunting techniques. [SANS]_

Testing

Use the descriptions and information from the resources in section
detection to simulate the persistence.

Furthermore, different tools provide checks to if detections work.

Atomic Red Team test suite
allows checking for specific MITRE ATT&CK persistence techniques, see e.g. T1044 "File
System Permissions
Weakness".

hasherezade published demos of
(also non standard) persistence methods used by malware, like COM hijacking.

Use PoisonApple to perform persistence techniques on macOS.

Use PANIX to perform persistence techniques against Linux systems, among others Debian and RHEL.

Use Diamorphine, a loadable kernel module (LKM) rootkit for Linux Kernels (x86/x86_64 and ARM64), to test the detection of LKMs.

Use AWSDoor: Persistence on AWS for adding access persistence on AWS. The corresponding article describes the techniques ad can use to hide themsel a cloud en and its AWSDoor implementation to simplify and automate the deployment of persistence techniques in AWS en.

Example

As an example we use the technique T1183 - "Image File Execution Options Injection" and abuse the "sticky keys" feature for executing a command shell. This would also be triggered before a login.

To test your collection tools, the pre mechanisms in place and
your awesome detections, execute the following for adding a debugger value for the
corresponding registry key:

Now you can click multiple times on the shift-key on your keyboard to trigger
the execution of cmd.

Response

If you respond to an incident and need to clean up malware persistence as a
temporary countermeasure, you just have to remove the gi. For
files and configuration changes it's mostly done using standard OS commands.
Use your EDR or some other frameworks (e.g. for Windows, see PowerSponse).

In special cases like WMI the cleanup is not as straightforward as with
other mechanisms, see blog post Removing Backdoors – Powershell Empire Edition:
1. remove the binding using Get-WmiObject __FilterToConsumerBinding -Namespace root\subscription | Where-Object { $_.filter -match 'evil'} | Remo;
1. remove the event consumer using Get-WmiObject CommandLineE -Namespace root\subscription -Filter "name='evil'" | Remo
1. remove the event filter using Get-WMIObject -Namespace root\Subscription -Class __E -Filter "Name='evil'" | Remo -

Then there were issues with null byte in the Windows registry and
attackers abused that to hide entries in e.g. run keys. Custom tools or the
RegDelNull
can be used to remo entries.

Pre

This list is in no way comprehensive and just lists some possibilities to prevent malware persistence. The most important thing would be of course to prevent the execution of unknown programs.
* Block file writes to unusual places if possible, e.g. public user
profile in Windows.
* Block file types on specific folders where only limited file types are used
(e.g. .exe in startup folder where only .lnk files should be placed).
* Use file integrity checking on important config files (e.g. cronjobs).
* Reduce pri so more ad persistence techniques would fail due to
missing pri.
* File system permissions should be checked regularly and be as restricted as
possible.
* Lock down configuration files (read-only) and on Windows put ACLs on
specific registry keys (like for the accessibility features keys).
* Prevent the abuse of third party identity pro, see Shadow Linking: The Persistence of SaaS Identity Threat.

For macOS there's the BlockBlock tool by Patrick Wardle which provides protection by monitoring persistence locations:

Tools

You can either collect the needed information once on a (remote) host in case of an incident or
collect the information on a regular basis for baselining and threat hunting.

One thing as a reminder and thanks to Harlan Carvey over at windowsir for
pointing out similar points too in blog posts, see Deep Knowledge,
and the Pursuit Thereof
and Troubleshooting and Deep
Knowledge:
Be cautious of the results of tools and try to cross check with different
tools or check things by hand. Tools only provide you the information in their
way and sometimes miss the malicious entry or some options were turned off
etc. Autoruns for example can hide Microsoft signed entries, but than some
LOLbin (li, abusing system tools so to say) commands were
missing. Use it to reduce the amount of entries, but know the limits. There
was a null byte issue with the registry and the entries were
missing too in the collection. New fixed the issue. One more: Persistence using
GlobalFlags in Image File Execution Options – Hidden from Autoruns.exe.

For collection of specific techniques see links and resources for
detection which co
information about the location of different persistence mechanisms.

Linux

* I'm not aware of a public a tool to get a bunch of persistence mechanisms. But
there are different commands which can be put into a script for easier
usage. Depending on the distribution use the corresponding commands for
crontab, cat, grep, md5sum, sha1sum, sha256sum, somethingsum
and directory listings for most of the techniques.
* Linux Security and Monitoring Scripts - Security and monitoring scripts you can use to monitor your Linux installation
for security-related events or for an in. Among other finding systemd unit files used for malware persistence.
* For regular collection of persistence mechanisms you can look into osquery or OSSEC.

MacOS

* KnockKnock
uncovers persistently installed software in order to generically
reveal such malware. See Github repository too for the source code.
* BlockBlock provides continual protection by monitoring persistence locations.
* Dylib Hijack Scanner or DHS, is a
simple utility that will scan your computer for applications that are either
susceptible to dylib hijacking or have been hijacked. See Github repository too for the source code.
* Besides the UI tool KnockKnock, I'm not aware of a public a command line tool
to get a bunch of persistence mechanisms. But there are different commands which can be put
into a script for easier usage. Use the corresponding commands for
crontab, cat, grep, md5sum, sha1sum, sha256sum, somethingsum
and directory listings for most of the techniques.
* For regular collection of persistence mechanisms you can look into
osquery or
OSSEC.

Windows

* A powerful persistence collection tool on Windows is
Autoruns. It
collects different categories and persistence information from a li and in
limited ways from offline images. There is a UI and a command line program
and the output format can be set to CS can then be imported into your
log collection system of choice.
* Instead of using CS and copy these file to the server, you can use
the script AutorunsToWinE.ps1 to convert the Autoruns output to Windows event
logs and rely on standard Windows event log forwarding.
* PowerShell of Autoruns.
* PersistenceSniper is a Powershell module to hunt for persistence implanted in Windows machines.
* RegRipper does also extracts
persistence mechanisms from the registry files directly.
* RECmd using the config file UserClassesASEPs extracts user's CLSID information.
* KAPE has different targets and modules, see KapeFiles which include persistence mechanisms, among others there's a collection of LNK files, scheduled task files and scheduled task listing or a WMI repository auditing module.
* PyrsistenceSniper is a Python-based offline Windows persistence detection tool. Point it at a KAPE dump, a collection, or a mounted disk image and get offline Windows persistence detection. Runs on Windows, Linux, and macOS.
* Different AVs and EDR tools also include the detection and pre of persistence mechanisms.

Cloud

* AWSDoor: Persistence on AWS for adding access persistence on AWS. The corresponding article describes the techniques ad can use to hide themsel a cloud en and its AWSDoor implementation to simplify and automate the deployment of persistence techniques in AWS en.

Github topic search for persistence

Currently not many things are found with these topics, but if you search for #malware and #persistence the matched repositories are listed:

Acknowledgement

Thanks to my previous employer Swisscom
(Github) for allowing me to publish the
information which was inspired by my work in the past few years at the
.

项目信息

开发语言：未知

Star 数：188

技术要点

该项目属于病毒分析方向的开源资源，代码结构清晰，适合安全研究人员学习参考。项目围绕Collection of malware persistence and hunting information. Be a persistent persistence hunter!展开，提供了可运行的实现，对理解相关安全机制、工具原理与攻防技术具有较高的研究价值。

从技术实现角度看，此类项目的核心在于对底层原理的深入理解与工程化落地。开发者在研究过程中可以结合官方文档与社区讨论，梳理项目的初始化流程、核心模块职责与数据流转，逐步掌握其中的技术细节与设计思路。

使用与学习建议

1. 下载源码压缩包，解压到本地环境。

2. 根据项目类型准备对应的运行环境与依赖。

3. 按照 README 中的步骤完成配置与部署。

4. 在隔离的测试环境中运行验证，避免影响生产系统。

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