Vishing is the practice of sending phishing emails to victims that appear to be voicemail alerts to acquire their Microsoft 365 and Outlook login information. Researchers at Zscaler's ThreatLabz said this email campaign, which resembles phishing emails from a few years ago, was discovered in May and is still active.
The researchers stated this month that the recent wave targets US organizations across various industries, including software security, security solution providers, the military, healthcare and pharmaceuticals, and the manufacturing and shipping supply chain.
An email is where it all begins
Attackers inform recipients of missed voicemails via email notifications that contain links to web-based attachments. Although many people don't check voicemail, audio messages on LinkedIn and WhatsApp have been there for a while, so using them to deceive consumers into clicking a link in an email can be successful.
Naturally, when the target clicks the link, they are taken to a credential phishing web page hosted on Japanese servers rather than a voicemail at all. The user gets directed to the Microsoft Office website or the Wikipedia page if the encoded email address at the end of the URL is missing.
The user is shown the final page, which is an Office 365 phishing page after they have correctly supplied the CAPTCHA information. The 2020 campaign Zscaler tracked using the same approach.
"Since they can persuade the victims to open the email attachments, voicemail-themed phishing attacks continue to be an effective social engineering strategy for attackers. This, together with the use of evasion techniques to get around automatic URL inspection tools, aids the threat actor in acquiring the users' credentials more successfully "reports Zscaler ThreatLabz.
Microsoft 365 Remains a Popular Victim
In a 2022 Egress research titled "Fighting Phishing: The IT Leader's View," it was found that 40% of firms utilizing Microsoft 365 reported becoming victims of credential theft, and 85% of organizations using Microsoft 365 reported being victims of phishing in the previous 12 months.
As the majority of businesses quickly transitioned to a primarily remote-work style, with many workers working from their homes, phishing usage continued to increase. It peaked during the peak of the COVID-19 pandemic in 2020 and 2021.
A substantial majority of credentials have been successfully compromised by the effort, which can be utilized for a number of different cybercrime endgames. These consist of taking control of accounts to gain access to files and data theft to send malicious emails that appear to be from a legitimate organization, and implanting malware,. The goal is to trick victims into using the same passwords for several accounts by adding the user ID/password combinations to credential-stuffing lists.
A rich mine of data that may be downloaded in bulk can usually be found in Microsoft 365 accounts, according to Robin Bell, CISO of Egress. Hackers may also use compromised Microsoft 365 accounts to send phishing emails to the victim's contacts in an effort to boost the success of their attacks.
