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Update BEC keyword item list in 3 queries
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petebryan committed Sep 19, 2023
1 parent be80500 commit a77f4ab
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Showing 3 changed files with 6 additions and 6 deletions.
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,7 @@ relevantTechniques:
tags:
- BEC
query: |
let BEC_Keywords = dynamic(['invoice','invoices','payment','payroll','paycheck','transfer','bank statement','bank details','wire','closing','funds','bank account','account details','iban','ACH','remit','remittance','purchase','deposit','pro-forma','bank',"platnosc","PO#","Zahlung","Rechnung","Paiement", "virement bancaire","Bankuberweisung","virement","hacked","phishing","payrollhelpdesk","direct deposit", "doc"]);
let BEC_Keywords = dynamic([ 'invoice','payment','paycheck','transfer','bank statement','bank details','closing','funds','bank account','account details','remittance','purchase','deposit',"PO#","Zahlung","Rechnung","Paiement", "virement bancaire","Bankuberweisung",'hacked','phishing']);
OfficeActivity
| where Operation =~ "New-InboxRule"
| where Parameters has "Deleted Items" or Parameters has "Junk Email" or Parameters has "DeleteMessage"
Expand All @@ -48,5 +48,5 @@ entityMappings:
fieldMappings:
- identifier: Address
columnName: ClientIPAddress
version: 1.0.0
version: 1.0.1
kind: Scheduled
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Expand Up @@ -16,7 +16,7 @@ relevantTechniques:
eventGroupingSettings:
aggregationKind: SingleAlert
query: |
let BEC_Keywords = dynamic(['invoice','invoices','payment','payroll','paycheck','transfer','bank statement','bank details','wire','closing','funds','bank account','account details','iban','ACH','remit','remittance','purchase','deposit','pro-forma','bank',"platnosc","PO#","Zahlung","Rechnung","Paiement", "virement bancaire","Bankuberweisung","virement","hacked","phishing","payrollhelpdesk","direct deposit", "doc"]);
let BEC_Keywords = dynamic([ 'invoice','payment','paycheck','transfer','bank statement','bank details','closing','funds','bank account','account details','remittance','purchase','deposit',"PO#","Zahlung","Rechnung","Paiement", "virement bancaire","Bankuberweisung",'hacked','phishing']);
// Adjust this threshold based on your environment
let sensitivity = 2.5;
let Events = materialize(imFileEvent
Expand Down Expand Up @@ -70,5 +70,5 @@ alertDetailsOverride:
alertDescriptionFormat: |
This query looks for users (in this case {{User}}) with suspicious spikes in the number of files accessed (in this case {{number_of_files_accessed}} events) that relate to topics commonly accessed as part of Business Email Compromise (BEC) attacks. The query looks for access to files in storage that relate to topics such as invoices or payments, and then looks for users accessing these files in significantly higher numbers than in the previous 14 days. Incidents raised by this analytic should be investigated to see if the user accessing these files should be accessing them, and if the volume they accessed them at was related to a legitimate business need.
This query contains thresholds to reduce the chance of false positives, these can be adjusted to suit individual environments. In addition false positives could be generated by legitimate, scheduled actions that occur less often than every 14 days, additional exclusions can be added for these actions on username or IP address entities. This query uses the imFileEvent schema from ASIM, you will first need to ensure you have ASIM deployed in your environment. Ref https://learn.microsoft.com/azure/sentinel/normalization-about-parsers
version: 1.0.0
version: 1.0.1
kind: Scheduled
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ relevantTechniques:
eventGroupingSettings:
aggregationKind: SingleAlert
query: |
let BEC_Keywords = dynamic(['invoice','invoices','payment','payroll','paycheck','transfer','bank statement','bank details','wire','closing','funds','bank account','account details','iban','ACH','remit','remittance','purchase','deposit','pro-forma','bank',"platnosc","PO#","Zahlung","Rechnung","Paiement", "virement bancaire","Bankuberweisung","virement","hacked","phishing","payrollhelpdesk","direct deposit"]);
let BEC_Keywords = dynamic([ 'invoice','payment','paycheck','transfer','bank statement','bank details','closing','funds','bank account','account details','remittance','purchase','deposit',"PO#","Zahlung","Rechnung","Paiement", "virement bancaire","Bankuberweisung",'hacked','phishing']);
// Adjust this threshold based on your environment
let sensitivity = 2.5;
let Events = materialize(AWSCloudTrail
Expand Down Expand Up @@ -61,5 +61,5 @@ alertDetailsOverride:
alertDescriptionFormat: |
This query looks for users (in this case {{UserIdentityUserName}}) with suspicious spikes in the number of files accessed (in this case {{CountOfDocs}})that relate to topics commonly accessed as part of Business Email Compromise (BEC) attacks. The query looks for access to files in AWS S3 storage that relate to topics such as invoices or payments, and then looks for users accessing these files in significantly higher numbers than in the previous 14 days. Incidents raised by this analytic should be investigated to see if the user accessing these files should be accessing them, and if the volume they accessed them at was related to a legitimate business need.
This query contains thresholds to reduce the chance of false positives, these can be adjusted to suit individual environments. In addition false positives could be generated by legitimate, scheduled actions that occur less often than every 14 days, additional exclusions can be added for these actions on username or IP address entities.
version: 1.0.1
version: 1.0.2
kind: Scheduled

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