Powershell Defender Disable Scan Feature

Severity: high
Author: Florian Roth (Nextron Systems)
Source: upstream

Detects requests to disable Microsoft Defender features using PowerShell commands

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1562.001` Impair Defenses: Disable or Modify Tools

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `all of selection_cli_cmdlet`

or:
CommandLine|contains: 'Add-MpPreference '
CommandLine|contains: 'Set-MpPreference '

Stage 2: `all of selection_cli_option`

or:
CommandLine|contains: 'DisableArchiveScanning '
CommandLine|contains: 'DisableBehaviorMonitoring '
CommandLine|contains: 'DisableBlockAtFirstSeen '
CommandLine|contains: 'DisableCatchupFullScan '
CommandLine|contains: 'DisableCatchupQuickScan '
CommandLine|contains: 'DisableIOAVProtection '
CommandLine|contains: 'DisableRealtimeMonitoring '

Stage 3: `all of selection_cli_value`

or:
CommandLine|contains: ' 1 '
CommandLine|contains: '$true'

Stage 4: `1 of selection_encoded_modifier`

or:
CommandLine|contains: 'DisableArchiveScanning '
CommandLine|contains: 'DisableBehaviorMonitoring '
CommandLine|contains: 'DisableBlockAtFirstSeen '
CommandLine|contains: 'DisableCatchupFullScan '
CommandLine|contains: 'DisableCatchupQuickScan '
CommandLine|contains: 'DisableIOAVProtection '
CommandLine|contains: 'DisableRealtimeMonitoring '
CommandLine|contains: 'disablearchivescanning '
CommandLine|contains: 'disablebehaviormonitoring '
CommandLine|contains: 'disableblockatfirstseen '
CommandLine|contains: 'disablecatchupfullscan '
CommandLine|contains: 'disablecatchupquickscan '
CommandLine|contains: 'disableioavprotection '
CommandLine|contains: 'disablerealtimemonitoring '

Stage 5: `1 of selection_encoded_direct`

or:
CommandLine|contains: 'EAGkAcwBhAGIAbABlAEIAZQBoAGEAdgBpAG8AcgBNAG8AbgBpAHQAbwByAGkAbgBnACAA'
CommandLine|contains: 'EAGkAcwBhAGIAbABlAEIAbABvAGMAawBBAHQARgBpAHIAcwB0AFMAZQBlAG4AIA'
CommandLine|contains: 'EAGkAcwBhAGIAbABlAEkATwBBAFYAUAByAG8AdABlAGMAdABpAG8AbgAgA'
CommandLine|contains: 'EAGkAcwBhAGIAbABlAFIAZQBhAGwAdABpAG0AZQBNAG8AbgBpAHQAbwByAGkAbgBnACAA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAQgBlAGgAYQB2AGkAbwByAE0AbwBuAGkAdABvAHIAaQBuAGcAIA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAQgBsAG8AYwBrAEEAdABGAGkAcgBzAHQAUwBlAGUAbgAgA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUASQBPAEEAVgBQAHIAbwB0AGUAYwB0AGkAbwBuACAA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAUgBlAGEAbAB0AGkAbQBlAE0AbwBuAGkAdABvAHIAaQBuAGcAIA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAYgBlAGgAYQB2AGkAbwByAG0AbwBuAGkAdABvAHIAaQBuAGcAIA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAYgBsAG8AYwBrAGEAdABmAGkAcgBzAHQAcwBlAGUAbgAgA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAaQBvAGEAdgBwAHIAbwB0AGUAYwB0AGkAbwBuACAA'
CommandLine|contains: 'QAaQBzAGEAYgBsAGUAcgBlAGEAbAB0AGkAbQBlAG0AbwBuAGkAdABvAHIAaQBuAGcAIA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBBAHIAYwBoAGkAdgBlAFMAYwBhAG4AbgBpAG4AZwA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBCAGUAaABhAHYAaQBvAHIATQBvAG4AaQB0AG8AcgBpAG4AZwAgA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBCAGwAbwBjAGsAQQB0AEYAaQByAHMAdABTAGUAZQBuACAA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBDAGEAdABjAGgAdQBwAEYAdQBsAGwAUwBjAGEAbgA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBDAGEAdABjAGgAdQBwAFEAdQBpAGMAawBTAGMAYQBuAA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBJAE8AQQBWAFAAcgBvAHQAZQBjAHQAaQBvAG4AIA'
CommandLine|contains: 'RABpAHMAYQBiAGwAZQBSAGUAYQBsAHQAaQBtAGUATQBvAG4AaQB0AG8AcgBpAG4AZwAgA'
CommandLine|contains: 'ZABpAHMAYQBiAGwAZQBiAGUAaABhAHYAaQBvAHIAbQBvAG4AaQB0AG8AcgBpAG4AZwAgA'
CommandLine|contains: 'ZABpAHMAYQBiAGwAZQBiAGwAbwBjAGsAYQB0AGYAaQByAHMAdABzAGUAZQBuACAA'
CommandLine|contains: 'ZABpAHMAYQBiAGwAZQBpAG8AYQB2AHAAcgBvAHQAZQBjAHQAaQBvAG4AIA'
CommandLine|contains: 'ZABpAHMAYQBiAGwAZQByAGUAYQBsAHQAaQBtAGUAbQBvAG4AaQB0AG8AcgBpAG4AZwAgA'
CommandLine|contains: 'kAGkAcwBhAGIAbABlAGIAZQBoAGEAdgBpAG8AcgBtAG8AbgBpAHQAbwByAGkAbgBnACAA'
CommandLine|contains: 'kAGkAcwBhAGIAbABlAGIAbABvAGMAawBhAHQAZgBpAHIAcwB0AHMAZQBlAG4AIA'
CommandLine|contains: 'kAGkAcwBhAGIAbABlAGkAbwBhAHYAcAByAG8AdABlAGMAdABpAG8AbgAgA'
CommandLine|contains: 'kAGkAcwBhAGIAbABlAHIAZQBhAGwAdABpAG0AZQBtAG8AbgBpAHQAbwByAGkAbgBnACAA'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`CommandLine`	match	`1` `$true` `Add-MpPreference` corpus 3 (sigma 3) `DisableArchiveScanning` `DisableBehaviorMonitoring` `DisableBlockAtFirstSeen` `DisableCatchupFullScan` `DisableCatchupQuickScan` `DisableIOAVProtection` `DisableRealtimeMonitoring` `EAGkAcwBhAGIAbABlAEIAZQBoAGEAdgBpAG8AcgBNAG8AbgBpAHQAbwByAGkAbgBnACAA` `EAGkAcwBhAGIAbABlAEIAbABvAGMAawBBAHQARgBpAHIAcwB0AFMAZQBlAG4AIA` `EAGkAcwBhAGIAbABlAEkATwBBAFYAUAByAG8AdABlAGMAdABpAG8AbgAgA` `EAGkAcwBhAGIAbABlAFIAZQBhAGwAdABpAG0AZQBNAG8AbgBpAHQAbwByAGkAbgBnACAA` `QAaQBzAGEAYgBsAGUAQgBlAGgAYQB2AGkAbwByAE0AbwBuAGkAdABvAHIAaQBuAGcAIA` `QAaQBzAGEAYgBsAGUAQgBsAG8AYwBrAEEAdABGAGkAcgBzAHQAUwBlAGUAbgAgA` `QAaQBzAGEAYgBsAGUASQBPAEEAVgBQAHIAbwB0AGUAYwB0AGkAbwBuACAA` `QAaQBzAGEAYgBsAGUAUgBlAGEAbAB0AGkAbQBlAE0AbwBuAGkAdABvAHIAaQBuAGcAIA` `QAaQBzAGEAYgBsAGUAYgBlAGgAYQB2AGkAbwByAG0AbwBuAGkAdABvAHIAaQBuAGcAIA` `QAaQBzAGEAYgBsAGUAYgBsAG8AYwBrAGEAdABmAGkAcgBzAHQAcwBlAGUAbgAgA` `QAaQBzAGEAYgBsAGUAaQBvAGEAdgBwAHIAbwB0AGUAYwB0AGkAbwBuACAA` `QAaQBzAGEAYgBsAGUAcgBlAGEAbAB0AGkAbQBlAG0AbwBuAGkAdABvAHIAaQBuAGcAIA` `RABpAHMAYQBiAGwAZQBBAHIAYwBoAGkAdgBlAFMAYwBhAG4AbgBpAG4AZwA` `RABpAHMAYQBiAGwAZQBCAGUAaABhAHYAaQBvAHIATQBvAG4AaQB0AG8AcgBpAG4AZwAgA` `RABpAHMAYQBiAGwAZQBCAGwAbwBjAGsAQQB0AEYAaQByAHMAdABTAGUAZQBuACAA` `RABpAHMAYQBiAGwAZQBDAGEAdABjAGgAdQBwAEYAdQBsAGwAUwBjAGEAbgA` `RABpAHMAYQBiAGwAZQBDAGEAdABjAGgAdQBwAFEAdQBpAGMAawBTAGMAYQBuAA` `RABpAHMAYQBiAGwAZQBJAE8AQQBWAFAAcgBvAHQAZQBjAHQAaQBvAG4AIA` `RABpAHMAYQBiAGwAZQBSAGUAYQBsAHQAaQBtAGUATQBvAG4AaQB0AG8AcgBpAG4AZwAgA` `Set-MpPreference` corpus 3 (sigma 3) `ZABpAHMAYQBiAGwAZQBiAGUAaABhAHYAaQBvAHIAbQBvAG4AaQB0AG8AcgBpAG4AZwAgA` `ZABpAHMAYQBiAGwAZQBiAGwAbwBjAGsAYQB0AGYAaQByAHMAdABzAGUAZQBuACAA` `ZABpAHMAYQBiAGwAZQBpAG8AYQB2AHAAcgBvAHQAZQBjAHQAaQBvAG4AIA` `ZABpAHMAYQBiAGwAZQByAGUAYQBsAHQAaQBtAGUAbQBvAG4AaQB0AG8AcgBpAG4AZwAgA` `disablearchivescanning` `disablebehaviormonitoring` `disableblockatfirstseen` `disablecatchupfullscan` `disablecatchupquickscan` `disableioavprotection` `disablerealtimemonitoring` `kAGkAcwBhAGIAbABlAGIAZQBoAGEAdgBpAG8AcgBtAG8AbgBpAHQAbwByAGkAbgBnACAA` `kAGkAcwBhAGIAbABlAGIAbABvAGMAawBhAHQAZgBpAHIAcwB0AHMAZQBlAG4AIA` `kAGkAcwBhAGIAbABlAGkAbwBhAHYAcAByAG8AdABlAGMAdABpAG8AbgAgA` `kAGkAcwBhAGIAbABlAHIAZQBhAGwAdABpAG0AZQBtAG8AbgBpAHQAbwByAGkAbgBnACAA`

Powershell Defender Disable Scan Feature

MITRE ATT&CK coverage

Event coverage

Stages and Predicates

Stage 1: all of selection_cli_cmdlet

Stage 2: all of selection_cli_option

Stage 3: all of selection_cli_value