Socially engineered SMS texts are being utilized to install malware on Android smartphones, as part of a large phishing operation that impersonates the Iranian government and social security authorities in order to steal credit card information and funds from victims' bank accounts,
Unlike other types of banking malware that use overlay attacks to steal sensitive data without the victim's knowledge, the financially motivated operation discovered by Check Point Research is developed to trick victims into handing over their credit card information by sending them a legitimate-looking SMS message with a link that, when clicked, downloads a malware-laced app onto their devices.
Check Point researcher Shmuel Cohen stated in a new report published Wednesday, "The malicious application not only collects the victim's credit card numbers, but also gains access to their 2FA authentication SMS, and turn[s] the victim's device into a bot capable of spreading similar phishing SMS to other potential victims."
As per the cybersecurity firm, it discovered hundreds of distinct phishing Android apps masquerading as device tracking apps, Iranian banks, dating and shopping sites, cryptocurrency exchanges, and government-related services, with these botnets sold as a "ready-to-use mobile campaign kit" on Telegram channels for somewhere between $50 and $150.
The infection chain of the smishing botnet begins with a bogus notification from the Iranian judiciary requesting users to evaluate a fictitious complaint made against the message's receivers. The complaint link takes victims to what appears to be a government website, where they are requested to provide personal information (e.g., name, phone number, etc.) and download an Android APK file.
Once downloaded, the rogue app not only demands invasive rights to execute operations typically not associated with such government applications, but it also displays a false login page that resembles Sana, the country's electronic judicial notice system, and prompts the victim to pay a $1 payment to proceed.
Users who choose to do so are then sent to a bogus payment page that captures the credit card information submitted, while the installed software acts as a covert backdoor to harvest one-time passcodes given by the credit card provider and assist more fraud.
Furthermore, the malware has a plethora of functionality, including the ability to exfiltrate all SMS messages received by a device to an attacker-controlled server, conceal its icon from the home screen to circumvent attempts to remove the app, deploy extra payloads, and obtain worm-like powers to broaden its attack surface.
Prevent data breaches
Cohen explained, "This allows the actors to distribute phishing messages from the phone numbers of typical users instead of from a centralized place and not be limited to a small set of phone numbers that could be easily blocked. This means that technically, there are no 'malicious' numbers that can be blocked by the telecommunication companies or traced back to the attacker."
To make matters worse, the attackers behind the operation were discovered to have inadequate operational security (OPSEC), enabling any third party to openly access the phone numbers, contacts, SMS messages, and list of any online bots stored on their servers.
"Stealing 2FA dynamic codes allows the actors to slowly but steadily withdraw significant amounts of money from the victims' accounts, even in cases when due to the bank limitations each distinct operation might garner only tens of dollars."
"Together with the easy adoption of the 'botnet as a service' business model, it should come as no surprise that the number of such applications for Android and the number of people selling them is growing," he added.
