Link Search Menu Expand Document

O365_Exchange_SetMailBox_ForwardingSmtpAddress

ID: 100461

Description:

Office365 Exchange Set-Mailbox ForwardingSmtpAddress action

Notes:

  • Rule will not trigger if UserId and ForwardingSmtpAddress share the same @domain

Repository: Fluency Group: Office365 Type: event

Default Status:

Enabled

Tags:  
O365 Exchange
   

Selector:

Query:

Filters:

Standard:

Field MUST hit
@fields.Operation Set-Mailbox
@fields.Workload Exchange
@fields.UserId exist (boolean)
@fields.ParametersFields.ForwardingSmtpAddress exist (boolean)
Field MUST NOT hit
@fields.UserType 4
  5

Additional JSON:

function json_doc_filter (doc)
   ui = doc['@fields'].UserId
   if ui == nil then
      return true
   end
   pf = doc['@fields'].ParametersFields
   addr = pf.ForwardingSmtpAddress
   if addr == nil then
      return true
   end
  domainpattern = "@%w+%.%a+"
  uidomainloc = string.find(ui, domainpattern)
   if uidomainloc == nil then
      return true
   end
   uirawdomain = string.sub(ui, uidomainloc)
   -- print("UI Raw Domain: "..uirawdomain)
   
   -- print(addr)
   addrdomainloc = string.find(addr, domainpattern)
   if addrdomainloc == nil then
      return true
   end
   addrrawdomain = string.sub(addr, addrdomainloc)
   -- print("addr Raw Domain: "..addrrawdomain)
   
   if uirawdomain == addrrawdomain then
      return false
   end
   return true
end
return json_doc_filter

Behavior Rule:

Key Type Behavior Category
@fields.UserId username application activity

Risks:

Risks Base Score Dimension
ALERT_NORMAL 100 alert
ALERT_POLICY 200 alert

Attributes:

Alias Key
Username @fields.UserId
Operation @fields.Operation
ResultStatus @fields.ResultStatus
ObjectId @fields.ObjectId
ExternalAccess @fields.ExternalAccess
ForwardingSmtpAddress @fields.ParametersFields.ForwardingSmtpAddress
DeliverToMailboxAndForward @fields.ParametersFields.DeliverToMailboxAndForward
IP @fields.ClientIP
Country @fields._ip.country
ISP @fields._ip.isp
Workload @fields.Workload

Correlation Rules:

First Occurrence:

Name Window Fields
NewUser 30 days @fields.UserId
  Risks: ML_NEW_USER
NewAddr 10 days @fields.ParametersFields.ForwardingSmtpAddress
  Risks: ML_NEW_CLIENT

History:

User Date
ho*d@fluencysecurity.com 2021 Sep 28 11:05:38 EDT
ho*d@fluencysecurity.com 2021 Sep 28 11:08:06 EDT
ho*d@fluencysecurity.com 2021 Sep 28 11:11:40 EDT
ho*d@fluencysecurity.com 2021 Sep 28 11:14:21 EDT
2021 Sep 30 17:58:10 EDT
ho*d@fluencysecurity.com 2022 Jan 27 20:07:42 EST
ke*y@fluencysecurity.com 2022 Feb 18 01:07:21 EST

This page was automatically created/formatted on Wed, 2022 May 4 21:43:53 EDT, from rule_dump.json (4d88bffdfb1cea26b3985f2193033606)