Posts

As a domain owner you always need to look out for threat actors launching domain spoofing attacks and phishing attacks to use your domain or brand name for carrying out malicious activities. No matter what email exchange solution you use, protecting your domain from spoofing and impersonation is imperative to ensure brand credibility and maintain trust among your esteemed customer-base. This blog will take you through the process of setting up your DMARC record for Office 365 users.

In recent times, a majority of businesses have made a shift towards using effective and robust cloud-based platforms and hosted email exchange solutions such as Office 365. Subsequently, cybercriminals have also upgraded their malicious techniques to conduct email fraud by outmanoeuvring the security solutions that are integrated into the platform. This is why Microsoft has extended support towards email authentication protocols like DMARC across all of its email platforms. But you should know how to correctly implement DMARC for Office 365, in order to fully utilize its benefits.

Why DMARC?

The first question that might arise is that, with anti-spam solutions and email security gateways already integrated into the Office 365 suite to block fake emails, why would you require DMARC for authentication? This is because while these solutions specifically protect against inbound phishing emails sent to your domain, DMARC authentication protocol gives domain owners the power to specify to receiving email servers how to respond to emails sent from your domain that fail authentication checks.

DMARC makes use of two standard authentication practices, namely SPF and DKIM to validate emails for authenticity. With a policy set to enforcement, DMARC can offer a high level of protection against impersonation attacks and direct-domain spoofing.

Do you really need DMARC while using Office 365?

There’s a common misconception among businesses, that having an Office 365 solution ensures safety from spam and phishing attacks. However, in May 2020, a series of phishing attacks on several Middle Eastern insurance firms using Office 365 caused significant data loss and an unprecedented amount of security breach. This is why simply relying on Microsoft’s integrated security solutions and not implementing external efforts for protecting your domain can be a huge mistake!

While Office 365’s integrated security solutions can offer protection against inbound security threats and phishing attempts, you still need to ensure that outbound messages sent from your own domain are authenticated effectively before landing into the inboxes of your customers and partners. This is where DMARC steps in.

Securing Office 365 against Spoofing and Impersonation with DMARC

Security solutions that come with the Office 365 suite act as spam filters that cannot secure your domain from impersonation, highlighting the need for DMARC. DMARC exists as a DNS TXT record in your domain’s DNS. For configuring DMARC for your domain, you need to:

Step 1: Identify valid email sources for your domain
Step 2: Set up SPF for your domain
Step 3: Set up DKIM for your domain
Step 4: Publish a DMARC TXT record in your domain’s DNS

You can use PowerDMARC’s free DMARC record generator to generate a record instantly with the correct syntax to publish in your DNS and configure DMARC for your domain. However, note that only an enforcement policy of reject can effectively help you mitigate impersonation attacks and domain abuse.

But is publishing a DMARC record enough? The answer is no. This takes us to our last and final segment which is DMARC reporting and monitoring.

5 Reasons Why You need PowerDMARC while Using Microsoft Office365

Microsoft Office 365 provides users with a host of cloud-based services and solutions along with integrated anti-spam filters. However despite of the various advantages, these are the drawbacks you might face while using it from a security perspective:

  • No solution for validating outbound messages sent from your domain
  • No reporting mechanism for emails failing authentication checks
  • No visibility into your email ecosystem
  • No dashboard to manage and monitor your inbound and outbound email flow
  • No mechanism to ensure your SPF record is always under 10 lookup limit

DMARC Reporting and Monitoring with PowerDMARC

PowerDMARC seamlessly integrates with Office 365 to empower domain owners with advanced authentication solutions that protects against sophisticated social engineering attacks like BEC and direct-domain spoofing. When you sign up with PowerDMARC you are signing up for a multi-tenant SaaS platform that not only assembles all email authentication best practices (SPF, DKIM, DMARC, MTA-STS, TLS-RPT and BIMI), but also provides an extensive and in-depth dmarc reporting mechanism, that offers complete visibility into your email ecosystem. DMARC reports on the PowerDMARC dashboard are generated in two formats:

  • Aggregate Reports
  • Forensic reports

We have strived to make the authentication experience better for you by solving various industry problems. We ensure encryption of your DMARC forensic reports as well as display aggregate reports in 7 different views for enhanced user-experience and clarity. PowerDMARC helps you monitor email flow and authentication failures, and blacklist malicious IP addresses from all over the world. Our DMARC analyzer tool aids you in configuring DMARC correctly for your domain, and shifting from monitoring to enforcement in no time!

 

Email is often the first choice for a cybercriminal when they’re launching because it’s so easy to exploit. Unlike brute-force attacks which are heavy on processing power, or more sophisticated methods that require a high level of skill, domain spoofing can be as easy as writing an email pretending to be someone else. In a lot of cases, that ‘someone else’ is a major software service platform that people rely on to do their jobs.

Which is what happened between 15th and 30th April, 2020, when our security analysts at PowerDMARC discovered a new wave of phishing emails targeting leading insurance firms in the Middle East. This attack has been just one among many others in the recent increase of phishing and spoofing cases during the Covid-19 crisis. As early as February 2020, another major phishing scam went so far as to impersonate the World Health Organization, sending emails to thousands of people asking for donations for coronavirus relief.

In this recent series of incidents, users of Microsoft’s Office 365 service received what appeared to be routine update emails regarding the status of their user accounts. These emails came from their organizations’ own domains, requesting users to reset their passwords or click on links to view pending notifications.

We’ve compiled a list of some of the email titles we observed were being used:

*account details changed for users’ privacy

You can also view a sample of a mail header used in a spoofed email sent to an insurance firm:

Received: from [malicious_ip] (helo= malicious_domain)

id 1jK7RC-000uju-6x

for [email protected]; Thu, 02 Apr 2020 23:31:46 +0200

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;

Received: from [xxxx] (port=58502 helo=xxxxx)

by malicious_domain with esmtpsa (TLSv1.2:ECDHE-RSA-AES2  56-GCM-SHA384:256)

From: “Microsoft account team” 

To: [email protected]

Subject: Microsoft Office Notification for [email protected] on 4/1/2020 23:46

Date: 2 Apr 2020 22:31:45 +0100

Message-ID: <[email protected]>

MIME-Version: 1.0

Content-Type: text/html;

charset=”utf-8″

Content-Transfer-Encoding: quoted-printable

X-AntiAbuse: This header was added to track abuse, please include it with any abuse report

X-AntiAbuse: Primary Hostname – malicious_domain

X-AntiAbuse: Original Domain – domain.com

X-AntiAbuse: Originator/Caller UID/GID – [47 12] / [47 12]

X-AntiAbuse: Sender Address Domain – domain.com

X-Get-Message-Sender-Via: malicious_domain: authenticated_id: [email protected]_domain

X-Authenticated-Sender: malicious_domain: [email protected]_domain

X-Source: 

X-Source-Args: 

X-Source-Dir: 

Received-SPF: fail ( domain of domain.com does not designate malicious_ip_address  as permitted sender) client-ip= malicious_ip_address  ; envelope-from=[email protected]; helo=malicious_domain;

X-SPF-Result: domain of domain.com does not designate malicious_ip_address  as permitted sender

X-Sender-Warning: Reverse DNS lookup failed for malicious_ip_address (failed)

X-DKIM-Status: none /  / domain.com /  /  / 

X-DKIM-Status: pass /  / malicious_domain / malicious_domain /  / default

 

Our Security Operation Center traced the email links to phishing URLs that targeted Microsoft Office 365 users. The URLs redirected to compromised sites at different locations around the world.

By simply looking at those email titles, it would be impossible to tell they were sent by someone spoofing your organization’s domain. We’re accustomed to a steady stream of work or account-related emails prompting us to sign into various online services just like Office 365. Domain spoofing takes advantage of that, making their fake, malicious emails indistinguishable from genuine ones. There’s virtually no way to know, without a thorough analysis of the email, whether it’s coming from a trusted source. And with dozens of emails coming in everyday, no one has the time to carefully scrutinize every one. The only solution would be to employ an authentication mechanism that would check all emails sent from your domain, and block only those that were sent by someone who sent it without authorization.

That authentication mechanism is called DMARC. And as one of the leading providers of email security solutions in the world, we at PowerDMARC have made it our mission to get you to understand the importance of protecting your organization’s domain. Not just for yourself, but for everyone who trusts and depends on you to deliver safe, reliable emails in their inbox, every single time.

You can read about the risks of spoofing here: https://powerdmarc.com/stop-email-spoofing/

Find out how you can protect your domain from spoofing and boost your brand here: https://powerdmarc.com/what-is-dmarc/