• Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
MUST READ

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 51

 | 

Security Affairs newsletter Round 530 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

The FBI warns that Scattered Spider is now targeting the airline sector

 | 

LapDogs: China-nexus hackers Hijack 1,000+ SOHO devices for espionage

 | 

Taking over millions of developers exploiting an Open VSX Registry flaw

 | 

OneClik APT campaign targets energy sector with stealthy backdoors

 | 

APT42 impersonates cyber professionals to phish Israeli academics and journalists

 | 

Kai West, aka IntelBroker, indicted for cyberattacks causing $25M in damages

 | 

Cisco fixed critical ISE flaws allowing Root-level remote code execution

 | 

U.S. CISA adds AMI MegaRAC SPx, D-Link DIR-859 routers, and Fortinet FortiOS flaws to its Known Exploited Vulnerabilities catalog

 | 

CitrixBleed 2: The nightmare that echoes the 'CitrixBleed' flaw in Citrix NetScaler devices

 | 

Hackers deploy fake SonicWall VPN App to steal corporate credentials

 | 

Mainline Health Systems data breach impacted over 100,000 individuals

 | 

Disrupting the operations of cryptocurrency mining botnets

 | 

Prometei botnet activity has surged since March 2025

 | 

The U.S. House banned WhatsApp on government devices due to security concerns

 | 

Russia-linked APT28 use Signal chats to target Ukraine official with malware

 | 

China-linked APT Salt Typhoon targets Canadian Telecom companies

 | 

U.S. warns of incoming cyber threats following Iran airstrikes

 | 

McLaren Health Care data breach impacted over 743,000 people

 | 
  • Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
  • Home
  • Security
  • Two-factor authentication, necessary but not sufficient to be safe

Two-factor authentication, necessary but not sufficient to be safe

Pierluigi Paganini May 29, 2013

Adoption of a two-factor authentication process is necessary  to increase the robustness for authentication processes, but security is a process that must be cured at 360 degrees.

Twitter finally deployed two-factor authentication to improve security of a user’s account, this is the response of popular social network to the various incidents occurred to some of its key customers such as the AP press.

The two-factor authentication process implemented by Twitter is SMS-based, user that will enable the security measure need to enter a password during the login phase, and then a subsequent six-digit access code. The short code is sent via text message to the user’s mobile making more difficult the hack of an account, the hacker in fact needs to have both user name and password for the account and need also to access to a user’s mobile registered for the two-factor authentication.

There are of course some side effect and vulnerabilities that could be considered when is deployed a two-factor authentication process.

In this post I try to explain them starting from two real recent cases :

Abuse of two-factor authentication process to lock a user’s account

A two-factor authentication feature could be abused to lock a customer’s user. According to F-Secure experts an attacker could lock the user’s Twitter account when he hasn’t enabled a two-factor authentication.

Security advisor at F-Secure, Sean Sullivan, demonstrated that an attacker could actually abuse this feature to prolong their unauthorized access to those accounts that don’t have two-factor authentication enabled.

If an attacker is able to acquire user’s credentials, for example with a phishing attack or any other social engineering technique, he could associate a prepaid phone number to the person’s account and enable the two-factor authentication. If a hacker succeeds to the association with a prepaid phone number the victim won’t be able to recover the account through a password reset and he will be forced to contact the Twitter support service.

The flaw in the process is the absence for a confirmation code necessary to add a number. (Confirmation is required to change the account’s associated e-mail address.) This is what the victim will see — even if they reset the account’s password.

two-factor authentication Twitter Flaw

 

When the two-factor authentication “Account Security” option is enabled for first time on the account settings page, Twitter asks users if they successfully received a test message sent to their phone. Users can simply click “yes,” even if they didn’t receive the message as demonstrated in the post by Sullivan.

“Instead, Twitter should send a confirmation link to the email address associated with the account for the account owner to click in order to confirm that two-factor authentication should be enabled, Sullivan said.”

This type of attack could be abused to prolong the time the victim could not access to the compromised accounts. Another problem related to the actual implementation of the two-factor authentication implemented by Twitter is related to those organizations that are geographically distributed on multiple sites and that allow the management of their Twitter account to different employees at the same time. In this scenario they cannot share a single phone number for authentication.

Be aware of malware

This is the second case that I desire to discuss. Despite the two-factor authentication introduce a further level of protection for user’s account a specifically crafted malware could elude the mechanisms as already happened in various contexts such as banking.

Recently for example it has been published the news related to a New Android Trojan that is able to evade the  two-factor authentication feature. An infected host, mobile or desktop, could make unsecure the authentication process, if malicious code is able to intercept the secure code sent for example via SMS forwarding it to the attacker.

Recently the Russian antivirus company Dr.Web detected a trojan that spreads as a security certificate that tricks users into thinking it must be installed onto their device, once installed the malware does nothing other than displaying a message stating “Certificate installed successfully and your device is protected now.”
Silently the malware collects mobile information (e.g. IMEI, model, carrier , phone number, OS) sending them to the command and control server.

At this point the attacker could instruct the mobile to intercept and forward SMS from specified senders for example in a two-factor authentication scenario, the malware in this way could catch the authentication code sent by out bank or by Twitter overcoming 2-step authentication feature.

What have we learned?

The adoption of additional authentication factors is necessary  to increase the security of the authentication processes, but security is a process that must be cured at 360 degrees.

Pierluigi Paganini

(Security Affairs – Security, Two-factor authentication)


facebook linkedin twitter

Android authentication F-Secure malware phishing attack Trojan Twitter two-factor authentication

you might also like

Pierluigi Paganini June 27, 2025
Taking over millions of developers exploiting an Open VSX Registry flaw
Read more
Pierluigi Paganini June 27, 2025
OneClik APT campaign targets energy sector with stealthy backdoors
Read more

leave a comment

newsletter

Subscribe to my email list and stay
up-to-date!

    recent articles

    SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 51

    Breaking News / June 29, 2025

    Security Affairs newsletter Round 530 by Pierluigi Paganini – INTERNATIONAL EDITION

    Breaking News / June 29, 2025

    The FBI warns that Scattered Spider is now targeting the airline sector

    Cyber Crime / June 28, 2025

    LapDogs: China-nexus hackers Hijack 1,000+ SOHO devices for espionage

    Malware / June 28, 2025

    Taking over millions of developers exploiting an Open VSX Registry flaw

    Hacking / June 27, 2025

    To contact me write an email to:

    Pierluigi Paganini :
    pierluigi.paganini@securityaffairs.co

    LEARN MORE

    QUICK LINKS

    • Home
    • Cyber Crime
    • Cyber warfare
    • APT
    • Data Breach
    • Deep Web
    • Digital ID
    • Hacking
    • Hacktivism
    • Intelligence
    • Internet of Things
    • Laws and regulations
    • Malware
    • Mobile
    • Reports
    • Security
    • Social Networks
    • Terrorism
    • ICS-SCADA
    • POLICIES
    • Contact me

    Copyright@securityaffairs 2024

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities...
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
    Non-necessary
    Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
    SAVE & ACCEPT