PS: This shouldn't mean that users should disable SMS or voice-based MFA for their accounts. Weinert says that users should enable a stronger MFA mechanism for their accounts, if available, recommending Microsoft's Authenticator MFA app as a good starting point.īut if users want the best, they should go with hardware security keys, which Weinert ranked as the best MFA solution in a blog post he published last year. The Microsoft exec believes that this gap between SMS & voice-based MFA 'will only widen' in the future.Īs MFA adoption increases overall, with more users adopting MFA for their accounts, attackers will also become more interested in breaking MFA methods, with SMS and voice-based MFA naturally becoming their primary target due to its large adoption. SMS and voice calls are the least secure MFA method todayĪll of these make SMS and call-based MFA 'the least secure of the MFA methods available today,' according to Weinert. Step 2: In the Emails & app accounts window, click your Microsoft account under Accounts used by email, calendar, and contacts and choose Manage. On top of these, phone networks are also exposed to changing regulations, downtimes, and performance issues, all of which impact the availability of the MFA mechanism overall, which, in turn, prevents users from authenticating on their account in moments of urgency. You need to make sure you are using a local account to login to Windows 10 and you don’t have any Microsoft account bind with any email or app.

SMS-based one-time codes are also phishable via open source and readily-available phishing tools like Modlishka, CredSniper, or Evilginx.įurther, phone network employees can be tricked into transferring phone numbers to a threat actor's SIM card - in attacks known as SIM swapping-, allowing attackers to receive MFA one-time codes on behalf of their victims. Weinert says that both SMS and voice calls are transmitted in cleartext and can be easily intercepted by determined attackers, using techniques and tools like software-defined-radios, FEMTO cells, or SS7 intercept services. The Microsoft exec cites several known security issues, not with MFA, but with the state of the telephone networks today. For the past year, Weinert has been advocating on Microsoft's behalf, urging users to embrace and enable MFA for their online accounts.Ĭiting internal Microsoft statistics, Weinert said in a blog post last year that users who enabled multi-factor authentication (MFA) ended up blocking around 99.9% of automated attacks against their Microsoft accounts.īut in a follow-up blog post today, Weinert says that if users have to choose between multiple MFA solutions, they should stay away from telephone-based MFA. The warning comes from Alex Weinert, Director of Identity Security at Microsoft. While robust passwords go a long way to securing your valuable online accounts, hardware-based two-factor authentication takes that security to the next level.

Microsoft account security alert