Monthly Archives: January 2021

Inbox Provider Insider Junk Scams

Inbox Providers work hard to stop email fraud and phishing scams from outside. Google, Yahoo! and Office365.com all utilize a mix of algorithms that include Blacklists, SPF, DKIM and DMARC compliance, Spam scoring and Relevance scoring to make inbox placement decisions. However, scammers have found an interesting loophole, by sending the spam from the Inbox Providers servers.

How does an Insider Scam work?

The trick to sending spammy email from within an Inbox Provider’s network is first to compromise an existing email box on the provider’s servers. This can be surprisingly easy! Google, Yahoo! and Office365.com have Millions of users. Corrupt one email box and a spammer can easily send email to every user on every domain that uses the Inbox Provider’s network. For example:

  • An email from a corrupted Gmail account never leaves the Gmail network when sent to Gmail Inboxes so the email may skip other Gmail spam safeguards like content scanning and Junk/Spam folder analysis.
  • An email sent from a Gmail account passes Blacklist, SPF, DKIM and DMARC for every domain using Gmail to send email, including emails sent outside the Gmail network, giving these emails a level of trust. A corrupted Gmail account therefore has the clout of Gmail behind it.

Inbox Providers have traditionally looked at Spam and Phishing as an external threat. With the transition of email from on-premise to cloud-based solutions, internal threats with compromised accounts will force Inbox Providers to change and adopt Internal Spam and Phishing analysis algorithms.

What can you do to protect your users?

You email users need to be aware that incoming email cannot be 100% trusted, even when using a reputable Inbox Provider. Invest in Fraud and Phishing training for your staff will raise awareness and help break some of the apathy with regard to security. Read up on more ways to recognize and combat Fraud and Phishing in our previous blog entry.

What can you do to protect your outbound email?

If you are not monitoring the quality of your outbound email, you are at risk for accidentally sending Fraud and Phishing emails from your Inbox Provider and other email sources. Every business should be monitoring Blacklisting, and SPF, DKIM and DMARC compliance from all email sources. With DMARC reporting, you receive feedback on how much of your email is passing SPF, DKIM and DMARC compliance to know how likely your email will make it to the Inbox of your recipients. MxToolbox Delivery Center provides all the information you need on email from your domain.

However, DMARC reporting and Strict DMARC policies will not prevent an Inbox Provider Insider attack using your domain name. For that, you need to use another feature of MxToolbox Delivery Center, Feedback Loops. Feedback Loops provide direct feedback from email recipients at different Inbox Providers on how each recipient views the email they received from you – Did it look like Spam, Phishing or Unsolicited Email? Did they unsubscribe?

Soon, Inbox Providers will implement algorithms to protect their users, scammers will find new ways to exploit your users and your domain for their own gain. In the meantime, beware the Inbox Provider Insider scams.

What’s in my Inbox? Recent Spam and Phishing attempts

Until social engineering fails as an exploit or it becomes unprofitable to scam companies and individuals via email, there will be Spam and Phishing. Spam and Phishing now accounts for more than 50% of global email traffic and has a diverse portfolio of subjects, origins, support websites and exploit software. Rather than getting overly technical, lets discuss the Junk in our own Inbox.

What’s Junk in My Inbox?

My Spam

I get some really boring spam. Home Warranties, Insurance, Credit and Retirement planning offers are the majority of my trash, but I get some interesting consumer spam around Wild Seafood and Diet Chocolate. Why seafood and diet chocolate? I have no idea. I only moderately like seafood and hate low-end chocolate. The rest make tremendous sense – all of them have a significant financial impact.

Keys to Recognizing Spam and Phishing

  • There is a financial incentive
  • There is an overwhelming sense of urgency
  • There is a need to login or check on your account – immediately
  • The origin is a company with which you have no connection
  • The subject line is strange or hyperbolic
  • Something is offered free

If you think it’s spam or phishing?

  • Don’t open it – Legitimate emails track open rates, and so do spammers. Fraudsters know who is a decent mark if you open it.
  • Don’t click on any links – In addition to showing the spammer that you are game, they’ll now have the opportunity to try to get you to download malware, provide login details or give them your credit card.
  • Don’t unsubscribe – You just told them that your email address is valid. Spammers will use it in other attempts. They are constantly refining their pitch and you just told them one of them failed.

Things you can do…

  • If you suspect this is a legitimate communication from a website you actually use – You can go directly to the website. Don’t click the email link, instead, Google the domain or go directly to the .com.
  • If you think it is a scam – Google the subject line or the sender. If it’s a scam other people may have questions about it and many security companies keep lists of spam subject lines.
  • If you must open it – You can Google some of the content or URLs in the content. That will give you information on the potential for scam. You can also use MxToolbox’s Spam Analyzer as a gauge to test the spaminess of the email.
  • Mark it as Junk – Every Inbox Provider has a method to mark an email as Junk or Spam. This feeds into their algorithms to detect new Junk and Spam. Marking it gives your Inbox Provider additional information in their pursuit of a Spam-free inbox.