Secret monthly fee

Issue 2 2022 Information Security

With an ever-growing number of smartphone users, the development of mobile applications has become a booming industry. Today there are millions of apps, helping users with almost every aspect of their everyday life from entertainment to banking and billing. With this in mind, cybercriminals are working hard to develop their own apps and benefit from unsuspecting users.

Kaspersky researchers have observed fraudsters actively spreading Trojans, which secretly subscribe users to paid services, disguised as various mobile apps, including popular games, healthcare apps and photo editors. Most of these Trojans request access to the user’s notifications and messages, so that the fraudsters can then intercept messages containing confirmation codes.

Users aren’t knowingly subscribing to these services but are, rather, falling victim to carelessness. For instance, a user fails to read the fine print and before they know it, they’re paying for a horoscope app. These victims often don’t realise these subscriptions exist until their mobile phone account runs dry earlier than expected.

According to Kaspersky researchers, the most widely-spread Trojans that sign users up to unwanted subscriptions are:

Jocker: Trojans from the Trojan.AndroidOS.Jocker family can intercept codes sent in text messages and bypass anti-fraud solutions. They're usually spread on Google Play, where scammers download a legitimate app from the store, add malicious code to it and then re-upload it under a different name. In most cases, these trojanised apps fulfil their purpose and the user never suspects that they’re a source of threat.

MobOk: MobOk is considered the most active of the subscription Trojans with more than 70% of mobile users encountering these threats. MobOk Trojan is particularly notable for an additional capability that, in addition to reading the codes from messages, enables it to bypass CAPTCHA. MobOK does this by automatically sending the image to a service designed to decipher the code shown.

Vesub: The Vesub Trojan is spread through unofficial sources and imitates popular games and apps, such as GameBeyond, Tubemate, Minecraft, GTA5 and Vidmate. This malware opens an invisible window, requests a subscription and then enters the code it intercepts from the victim’s received text messages. After that the user is subscribed to a service without their knowledge or consent.

Most of these apps lack any legitimate functionality. They subscribe users as soon as they are launched while victims just see a loading window. However, there are some examples, such as a fake GameBeyond app, where the detected malware is actually accompanied by a random set of functional games.

GriftHorse.l: Unlike the Trojans mentioned above, this one does not subscribe victims to a third-party service – instead it uses its own. Users end up subscribing to one of these services by simply not reading the user agreement carefully. For example, there are apps that have recently spread intensively on Google Play, offering to tailor personal weight-loss plans for a token fee. Such apps contain small print mentioning a subscription fee with automatic billing. This means money will be deducted from the user's bank account on a regular basis without needing any further confirmation from the user.

“Apps can help us stay connected, fit, entertained and generally make our lives easier. There are multiple mobile apps appearing every day, for every taste and purpose – unfortunately, cybercriminals are using this to their advantage. Some of the apps are designed to steal money by subscribing users to unwanted services. These threats are preventable, which is why it’s important to be aware of the signs that give away trojanised apps. Even if you trust an app, you should avoid granting it too many permissions. Only allow access to notifications for apps that need it to perform their intended purposes, for example, to transfer notifications to wearable devices. Apps for something like themed wallpapers or photo editing don't need access to your notifications,” comments Igor Golovin, security expert at Kaspersky.

Learn more at www.kaspersky.co.za


Credit(s)




Share this article:
Share via emailShare via LinkedInPrint this page



Further reading:

Highest increase in global cyberattacks in two years
Information Security News & Events
Check Point Global Research released new data on Q2 2024 cyber-attack trends, noting a 30% global increase in Q2 2024, with Africa experiencing the highest average weekly per organisation.

Read more...
Cybersecurity a challenge in digitalising OT
Kaspersky Information Security Industrial (Industry)
According to a study by Kaspersky and VDC Research on securing operational technology environments, the primary risks are inadequate security measures, insufficient resources allocated to OT cybersecurity, challenges surrounding regulatory compliance, and the complexities of IT/OT integration.

Read more...
Cybersecurity in South Africa
Information Security
According to the Allianz Risk Barometer 2025, cyber incidents, including ransomware attacks, data breaches and IT outages, are now the top global business risk, marking their fourth year at the top.

Read more...
Are AI agents a game-changer?
Information Security
While AI-powered chatbots have been around for a while, AI agents go beyond simple assistants, functioning as self-learning digital operatives that plan, execute, and adapt in real time. These advancements do not just enhance cybercriminal tactics, they may fundamentally change the battlefield.

Read more...
Disaster recovery vs cyber recovery
Information Security
Disaster recovery centres on restoring IT operations following events like natural disasters, hardware failures or accidents, while cyber recovery is specifically tailored to address intentional cyberthreats such as ransomware and data breaches.

Read more...
Back-up securely and restore in seconds
Betatrac Telematic Solutions Editor's Choice Information Security Infrastructure
Betatrac has a solution that enables companies to back-up up to 8 TB of data onto a device and restore it in 30 seconds in an emergency, called Rapid Access Data Recovery (RADR).

Read more...
The rise of AI-powered cybercrime and defence
Information Security News & Events AI & Data Analytics
Check Point Software Technologies launched its inaugural AI Security Report, offering an in-depth exploration of how cybercriminals are weaponising artificial intelligence (AI), alongside strategic insights defenders need to stay ahead.

Read more...
The deepfake crisis is here and now
Information Security Training & Education
Deepfakes are a growing cybersecurity threat that blur the line between reality and fiction. These AI-generated synthetic media have evolved from technological curiosities to sophisticated weapons of digital deception, costing companies upwards of $600 000 each.

Read more...
What does Agentic AI mean for cybersecurity?
Information Security AI & Data Analytics
AI agents will change how we work by scheduling meetings on our behalf and even managing supply chain items. However, without adequate protection, they become soft targets for criminals.

Read more...
Phishing attacks through SVG image files
Kaspersky News & Events Information Security
Kaspersky has detected a new trend: attackers are distributing phishing emails to individual and corporate users with attachments in SVG (Scalable Vector Graphics) files, a format commonly used for storing images.

Read more...