Skip to main content

Search for Credit Card numbers in Address Book\Contact data using EWS

Information security and data breaches are a hot topic at the moment, there seems to be a constant stream of data breaches and vulnerabilities in different products being exploited on a daily basis. One topic that was brought up in the last few weeks has been Address Book data . Address books can be the proverbial open window on the house with bars on door and maybe not something that is commonly thought about. 

If you want to detect if people are using Address book to store confidential information it can be a challenge because this data isn't searchable via a conventional eDiscovery type search. But this is where a scripted enumeration and filtering approach can do the job.

I posted a Contacts Powershell module that consolidated a lot of EWS contacts function into one script last year so for this post I've extended this to include a Search that will enumerate all the contacts in a Mailbox's contacts folder and Search for Credit Card Number and Social Security Numbers being stored in any of the Phone number properties and email address properties. The script I've posted does some filtering to separate out the Host part of email address to test so for example if somebody puts the 12345678@fakedomain it will separate out 12345678 to test.

Searching for Credit Card Numbers

To Search for Credit card number you basically need two ingredients, the first is the luhn algorithm which is a Modulus 10 algorithm that will validate if a number sequence is a credit card number. Then you run a number of Regex patterns to determine the type of card and who issued it. The good thing is there are plenty libraries up on GitHub that will  already do this so there is no need to write any code for this. The one I decided to use was

Searching for Social Security Numbers (or your own custom RegEx)

To Search for SSI I've used the Google Braintrust Regex of

$SSN_Regex = "^(?!000)([0-6]\d{2}|7([0-6]\d|7[012]))([ -]?)(?!00)\d\d\3(?!0000)\d{4}$"

I've posted up the script for this I've put a compiled version of the creditcard validation library I used which need to be in the same directory as the module here

To Run the script you just use something like the following to produce a report of any hits in  a Mailbox. Note because of the Regexs used for the SSI and the fact that phone numbers can easily look like validate credit card numbers this script can produce a large number of false positives.

Search-ContactsForCCNumbers -MailboxName | Export-csv -NoTypeInformation -Path c:\temp\CCrep.csv

Popular posts from this blog

Export calendar Items to a CSV file using EWS and Powershell

Somebody asked about this last week and while I have a lot of EWS scripts that do access the Calendar I didn't have a simple example that just exported a list of the Calendar events with relevant information to a CSV file so here it is.

I've talked on this one before in this howto  but when you query the calendar folder using EWS you need to use a CalendarView which will expand any recurring appointments in a calendar. There are some limits when you use a calendarview in that you can only return a maximum of 2 years of appointments at a time and paging will limit the max number of items to 1000 per call. So if you have a calendar with a very large number of appointments you need to break your query into small date time blocks. In this example script I'm just grabbing the next 7 days of appointments if you want to query a longer period you need to adjust the following lines (keeping in mind what I just mentioned)

#Define Date to Query
$StartDate = (Get-Date)
$EndDate = (Ge…

EWS Managed API and Powershell How-To series Part 1

I thought I'd start the year with a series of posts that goes back over the basics of using the EWS Managed API from Powershell and provides a modular remarked example that you can easily cut and paste to build your own scripts. Along the way in this series I'll show a whole bunch of examples around specific things.

As a starting point for versions this will be Powershell Version 2.0  and the EWS Managed API 1.1 (which will soon change to 1.2 once released)

The starting point for any EWS script your going to write is connecting to Exchange for which there are three important pieces of information you will need. Firstly you need to know the version of Exchange your running in this script its going to be held in the following variable

$ExchangeVersion = [Microsoft.Exchange.WebServices.Data.ExchangeVersion]::Exchange2010_SP1

Other valid values for Exchange 2007 would be

$ExchangeVersion = [Microsoft.Exchange.WebServices.…

Microsoft Teams Private Chat History Addin for Outlook

Being somebody who is transitioning across from Skype for Business to Teams one of things I missed the most (and found the most frustrating) is the lack of the ability in Outlook and OWA to view the conversation history from Online meetings and private chats in Microsoft Teams. This is especially frustrating when you have an external meeting and your sent an IM that contains some vital information for what you need to do. This information is tracked in your mailbox for compliance reasons in the Teams Chat folder but this folder is hidden so it not accessible to the clients and must be extracted by other means eg. Most people seem to point to doing a compliance search if you need this data .

Given that the information is in my mailbox and there shouldn't be any privacy concern around accessing it I looked at a few ways of getting access to these TeamsChat messages in OWA and Outlook the first way was using …
All sample scripts and source code is provided by for illustrative purposes only. All examples are untested in different environments and therefore, I cannot guarantee or imply reliability, serviceability, or function of these programs.

All code contained herein is provided to you "AS IS" without any warranties of any kind. The implied warranties of non-infringement, merchantability and fitness for a particular purpose are expressly disclaimed.