eradicating-malware-from-infected-systems

name	eradicating-malware-from-infected-systems
description	Systematically map and remove malware, backdoors, and attacker persistence mechanisms (registry Run keys, scheduled tasks, WMI subscriptions, services, cron/init.d) from infected Windows and Linux systems using Autoruns, EDR/AV, and YARA, restoring a clean state while preventing re-infection. Use after containment and forensic analysis have identified all compromised systems and persistence mechanisms and you are ready to eradicate and recover.
domain	cybersecurity
subdomain	incident-response
tags	["incident-response","eradication","malware-removal","persistence","dfir"]
mitre_attack	["T1486","T1490","T1070","T1078","T1547"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["RS.MA-01","RS.MA-02","RS.AN-03","RC.RP-01"]

Eradicating Malware from Infected Systems

When to Use

• Malware infection confirmed and containment is in place
• Forensic investigation has identified all persistence mechanisms
• All compromised systems have been identified and scoped
• Ready to remove attacker artifacts and restore clean state
• Post-containment phase requires systematic cleanup

Prerequisites

• Completed forensic analysis identifying all malware artifacts
• List of all compromised systems and accounts
• EDR/AV with updated signatures deployed
• YARA rules for the specific malware family
• Clean system images or verified backups for restoration
• Network isolation still in effect during eradication

Workflow

Step 1: Map All Persistence Mechanisms

# Windows - Check all known persistence locations
# Autoruns (Sysinternals) - comprehensive autostart enumeration
autorunsc.exe -accepteula -a * -c -h -s -v > autoruns_report.csv

# Registry Run keys
reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /s
reg query "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /s
reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce" /s
reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run" /s

# Scheduled tasks
schtasks /query /fo CSV /v > schtasks_all.csv

# WMI event subscriptions
Get-WMIObject -Namespace root\Subscription -Class __EventFilter
Get-WMIObject -Namespace root\Subscription -Class CommandLineEventConsumer
Get-WMIObject -Namespace root\Subscription -Class __FilterToConsumerBinding

# Services
Get-Service | Where-Object {$_.Status -eq 'Running'} | Select-Object Name, DisplayName, BinaryPathName

# Linux persistence
cat /etc/crontab
ls -la /etc/cron.*/
ls -la /etc/init.d/
systemctl list-unit-files --type=service | grep enabled
cat /etc/rc.local
ls -la ~/.bashrc ~/.profile ~/.bash_profile

Step 2: Identify All Malware Artifacts