Tuesday, September 20, 2016

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 https://www.wired.com/2016/09/people-please-dont-store-private-data-address-book/ . 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 https://github.com/gustavofrizzo/CreditCardValidator

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 https://github.com/gscales/Powershell-Scripts/blob/master/EWSContacts/EWSContactFunctions.ps1 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 https://github.com/gscales/Powershell-Scripts/raw/master/EWSContacts/CreditCardValidator.dll

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 mailbox@domain.com | Export-csv -NoTypeInformation -Path c:\temp\CCrep.csv

Friday, September 02, 2016

How to Like\Unlike an Item using EWS in Exchange Online

Likes and Mentions are a new feature in Exchange Online (in OWA) that was introduced late last year in First Release for Office365. With the focused Inbox now being rolled out to replace clutter these are some of the new social user curation type features that could change the user experience (hopefully for the better) in the coming years. While none of these features are new to those people using other Social platforms like facebook, twitter etc they do offer a world of new possibilities to those that have a little imagination.

In this post I'm going to look at how you can Like an item using Exchange Web Services eg

Currently there is no real documentation on the use of Likes in any API or how they are delivered in Exchange Online so care should be taken as this may mean the feature is subject to change in any of the future service updates.

Versioning your Requests

To use likes fully you need to make sure you version your EWS requests (which involves setting the ServerRequestVersion in the SOAP header) to V2015_10_05 or higher.  The Like information is returned by Exchange as a Strongly Type property in EWS (LikeType). If you look at a Response that includes the Like information in the SOAP response you should see both Like and LikePreview returned eg

      <t:Name>Glen Scales</t:Name>
    <t:Name>Glen Scales</t:Name>

If you have the latest proxy objects from the Exchange Online WSDL then you should see the Likes and LikePreview property collections in the ItemType Class. In the latest EWS Managed API from github https://github.com/OfficeDev/ews-managed-api only the Likes class is currently available.

Liking an Item (Unsupported)

The EWS LikeItem operation currently has no definition in the Services.WSDL so liking an Item via EWS is currently unsupported. However you can still use the operation as long as you construct the request using Raw SOAP message eg a request to like or unlike and item using EWS look like

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
    <t:RequestServerVersion Version="V2015_10_05"/>
  <soap:Body xmlns="http://schemas.microsoft.com/exchange/services/2006/messages">
      <ItemId Id="AAM.." ChangeKey="CQA.."/>

As this is an unsupported operation if you do something like try to like the same item twice you will get a 500 error rather then a nice SOAP based error response. I've put together a scrip that allows you to search for an Item via subject and like or unlike it using EWS. I've put this up on GitHub here https://github.com/gscales/Powershell-Scripts/blob/master/EWSLIkeMessage.ps1