This is the first of a series of posts on threats and risks we've found using Interlock.
A few days ago, we were walking a customer through the results of their Interlock Test Drive. While examining one of the Bad users, the customer interrupted the demonstration, saying "That's not right. That user shouldn't be in Oregon." We took a closer look at the identity in question, and found something troubling: the user's internal, Exchange email account was being logged into by an automated system hosted in AWS.
A bit of background. Interlock uses advanced Identity Analytics to evaluate the risk each identity poses to the organization based on their characteristics and activities over time. Identities that pose a large risk are flagged as Bad and bubbled up to the user interface to be evaluated (though they can also be mitigated automatically or generate out-of-band alerts). The identity we were looking at had been flagged as bad precisely because it looked like abnormal access: out of the user's and organization's normal operating locations, from a new IP assocated with a new location some distance away, with a new device type.
We ran a WHOIS search on the IP address of the access, and it was an AWS account.
NetRange: XXX.XXX.0.0 - XXX.XXX.255.255 CIDR: XXX.XXX.0.0/12 NetName: AMAZON NetHandle: XXX-XXX-XXX-XXX-XXX Parent: XXXX (XXX-XXX-XXX-XXX-XXX) NetType: Direct Allocation OriginAS: Organization: Amazon Technologies Inc. (AT-88-Z) RegDate: 2014-10-23 Updated: 2014-11-13 Ref: http://whois.arin.net/rest/net/XXX-XXX-XXX-XXX-XXX OrgName: Amazon Technologies Inc. OrgId: AT-88-Z Address: 410 Terry Ave N. City: Seattle StateProv: WA PostalCode: 98109 Country: US RegDate: 2011-12-08 Updated: 2014-10-20 Comment: All abuse reports MUST include: Comment: * src IP Comment: * dest IP (your IP) Comment: * dest port Comment: * Accurate date/timestamp and timezone of activity Comment: * Intensity/frequency (short log extracts) Comment: * Your contact details (phone and email) Without these we will be unable to identify the correct owner of the IP address at that point in time. Ref: http://whois.arin.net/rest/org/AT-88-Z OrgAbuseHandle: AEA8-ARIN OrgAbuseName: Amazon EC2 Abuse OrgAbusePhone: +1-206-266-4064 OrgAbuseEmail: email@example.com OrgAbuseRef: http://whois.arin.net/rest/poc/AEA8-ARIN OrgNOCHandle: AANO1-ARIN OrgNOCName: Amazon AWS Network Operations OrgNOCPhone: +1-206-266-2187 OrgNOCEmail: firstname.lastname@example.org OrgNOCRef: http://whois.arin.net/rest/poc/AANO1-ARIN OrgTechHandle: ANO24-ARIN OrgTechName: Amazon EC2 Network Operations OrgTechPhone: +1-206-266-4064 OrgTechEmail: email@example.com OrgTechRef: http://whois.arin.net/rest/poc/ANO24-ARIN
Not good. Somehow, a system in AWS had the identity's credentials and
was logging into the organization's Exchange account. Digging in deeper,
we looked at the claimed User Agent string of the activity and found that it was claiming to be
Outlook-iOS-Android/1.0. A Google search turned up this
indicating that the User Agent string is associated with the new (at
least to Microsoft, more on that in a moment) Outlook for iOS and
Android apps (or something masquerading as such). So why is it in AWS?
We collect and process your email address and credentials to provide you the Service.
We collect and process your email messages and associated content to provide you the Service.
In other words, in order to provide the quality of service they wanted for Outlook for iOS and Android, they are caching both credentials and email data on their own servers.
For the casual, personal user of Office365, this is probably no big deal, but for enterprise customers, particularly ones constrained by compliance requirements, this may be unacceptable. Enterprise data and credentials are being copied and stored on third-party servers. This is a violation of the security policies of many (most?) organizations.
According to the comments by Microsoft personnel, these are valid concerns. Organizations who want to limit their exposure to this issue can use the ActiveSync Allow/Block/Quarantine list feature of Exchange 2010+ (or see this article for older versions) to limit or block the access of this app. Of course, this may still result in credentials being cached even if they are blocked by Exchange, so some user education is probably also in order.
If you're interested in finding potential threats like this automatically as they arise in the future, please contact us to take a test drive of Interlock.