New Office 365 Phishing Scams Detected

Two new Office 365 phishing scams have been detected in the past few days. One scam uses a fake Office 365 site to deliver the Trickbot Trojan and the other is a spear phishing campaign targeting Office 365 administrators to capture their credentials.

The Trickbot campaign uses a realistic domain – get.office365.live – that has all the typical elements of a genuine Microsoft website, including links to Microsoft resources. The website, identified by MalwareHunterTeam, detects the visitor’s browser and displays a popup within a few seconds of landing on the website.

A different warning is displayed for Firefox and Chrome users, with the associated logos. The warning comes from either the Chrome or Firefox Update Center. The message states that the user has an older version of the browser, which may cause incorrect site mapping, loss of all stored and personal data, and browser errors. An update button is supplied to download the browser update.

If the update button is clicked, it triggers the download of an executable file called upd365_58v01.exe. If that executable is run, the Trickbot Trojan will be downloaded and inserted into a svchost.exe process. That makes it harder for the user to detect the information stealer through Task Manager.

The Trickbot Trojan has several capabilities. It is a banking Trojan that can intercept banking credentials using webinjects. It also contains a password grabbing module which steals saved login credentials, autofill information, browsing history, and Bitcoin wallets. The malware also serves as a downloader for other malware variants and a module also been developed for propagation which includes the EternalBlue exploit.

Once installed, the malware stays in continuous contact with its C2. Due to the obfuscation methods used, the infection is unlikely to be detected by an end user, but the network admin may notice unusual traffic or attempts to connect to blacklisted domains.

This is a professional campaign that is likely to fool many end users. It is currently unclear whether traffic is being directed to the site through malvertising redirects or phishing emails.

Office 365 Admins Targeted

A phishing campaign has been detected which is targeting Office 365 administrators. Fake browser warnings are used to trick admins into disclosing their login credentials.

Emails have been constructed using the Microsoft and Office 365 logos which contain a warning about an aspect of Office 365 which requires the admin’s immediate attention. One message warns the admin about a mail redirect on an Office 365 inbox which indicates there has been an account compromise. Another advises the admin that the company’s Office 365 licenses have expired.

The emails contain a link for the admin to use to login to their Office 365 account to address the problem. The user will be directed to a webpage on the windows.net domain which has a valid certificate from Microsoft. The Microsoft login box is identical to that used on the Microsoft site.

Most admins will be vigilant and wary of warnings such as these. Even if the links are clicked, admins are likely to check the domain to make sure it is genuine. However, these scams are conducted because they do work. Some admins will be fooled and will disclose their credentials.

Admin credentials are highly valuable as they allow an attacker to create new office 365 accounts, access other user’s mailboxes, and send phishing emails from other accounts on the domain. These targeted attacks on admins are becoming more common due to the high value of the accounts and the range of attacks they allow a hacker to perform.

There is no single cybersecurity solution that will provide total protection from phishing attacks. What is needed is a defense in depth approach. End users should be provided with ongoing security awareness training to ensure they are aware of the most common threats and know how to identify potential scams. Phishing simulations are useful for gauging how effective training has been.

However, the priority must be to block these attacks and prevent end users from being tested. An advanced spam filter such as SpamTitan blocks more than 99.97% of spam and phishing emails. SpamTitan scans all incoming messages for malware and uses dual anti-virus engines for greater accuracy. A sandboxing feature has also now been added to allow the safe execution and analysis of suspicious email attachments.

WebTitan serves as an additional security layer that prevents end users from visiting malicious websites. The DNS filter can be used to exercise control over the types of websites that can be visited by employees and blocks all attempts to visit blacklisted websites, such as those that have been used for malware distribution, scams, or phishing.

Contact TitanHQ today to find out more about SpamTitan and WebTitan for SMBs and MSPs, the different deployment options, pricing information, and to book a product demonstration.

New Office 365 Phishing Scams Detected FAQ

Will a spam filter block all spam and phishing emails?

No spam filter will be 100% effective, 100% of the time, which is why it is important to implement layered defenses. Many spam filters block around 99% of spam. SpamTitan is an advanced spam filter that has been independently verified as blocking 99.97% of spam email with a low false positive rate of just 0.03%.

How does email content filtering work?

Once initial checks have been performed to identify malware and emails from known spam sources, message content filtering takes place. Email content is analyzed, and each email is assigned a spam score based on phrases, keywords, images, and hyperlinks. A threshold is set and if that score is reached, the message will be rejected or quarantined.

What is greylisting and why is it important?

Greylisting is an important spam filtering mechanism for detecting new sources of spam. Greylisting initially rejects an email and requests the message is resent. Since email servers being used for spamming are busy sending huge volumes of messages, they do not respond to these requests or there is a significant delay. The delay is a good indicator that the message is spam.

Why should I scan outbound emails?

Outbound scanning is important for several reasons. By scanning outbound emails, email account compromises can be detected quickly to block business email compromise attacks. Attempts to use internal email accounts for sending malware and spam will be blocked, and tags can be applied to certain data types to identify attempted data theft by malicious insiders.