Changes to AWS Security Group ingress and egress settings

Back


Id	4f19d4e3-ec5f-4abc-9e61-819eb131758c
Rulename	Changes to AWS Security Group ingress and egress settings
Description	A Security Group acts as a virtual firewall of an instance to control inbound and outbound traffic. Hence, ingress and egress settings changes to AWS Security Group should be monitored as these can expose the enviornment to new attack vectors.
Severity	Low
Tactics	Persistence
Techniques	T1098
Required data connectors	AWS AWSS3
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_IngressEgressSecurityGroupChange.yaml
Version	1.0.4
Arm template	4f19d4e3-ec5f-4abc-9e61-819eb131758c.json

KQL

let EventNameList = dynamic([ "AuthorizeSecurityGroupEgress", "AuthorizeSecurityGroupIngress", "RevokeSecurityGroupEgress", "RevokeSecurityGroupIngress"]);
AWSCloudTrail
| where EventName in~ (EventNameList)
| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
| summarize EventCount=count(), StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated)
by EventSource, EventName, UserIdentityType, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,
AdditionalEventData, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements
| extend timestamp = StartTimeUtc

YAML

relevantTechniques:
- T1098
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  - columnName: RecipientAccountId
    identifier: CloudAppAccountId
- entityType: IP
  fieldMappings:
  - columnName: SourceIpAddress
    identifier: Address
version: 1.0.4
id: 4f19d4e3-ec5f-4abc-9e61-819eb131758c
severity: Low
kind: Scheduled
queryFrequency: 1d
description: |
  'A Security Group acts as a virtual firewall of an instance to control inbound and outbound traffic.
   Hence, ingress and egress settings changes to AWS Security Group should be monitored as these can expose the enviornment to new attack vectors. '  
requiredDataConnectors:
- connectorId: AWS
  dataTypes:
  - AWSCloudTrail
- connectorId: AWSS3
  dataTypes:
  - AWSCloudTrail
triggerOperator: gt
name: Changes to AWS Security Group ingress and egress settings
tactics:
- Persistence
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Amazon Web Services/Analytic Rules/AWS_IngressEgressSecurityGroupChange.yaml
triggerThreshold: 0
queryPeriod: 1d
query: |
  let EventNameList = dynamic([ "AuthorizeSecurityGroupEgress", "AuthorizeSecurityGroupIngress", "RevokeSecurityGroupEgress", "RevokeSecurityGroupIngress"]);
  AWSCloudTrail
  | where EventName in~ (EventNameList)
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
  | summarize EventCount=count(), StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated)
  by EventSource, EventName, UserIdentityType, RecipientAccountId, AccountName, AccountUPNSuffix, SourceIpAddress, UserAgent, SessionMfaAuthenticated, AWSRegion,
  AdditionalEventData, UserIdentityAccountId, UserIdentityPrincipalid, ResponseElements
  | extend timestamp = StartTimeUtc  
status: Available

ARM