The faucet-estry of threats concentrating on Hamster Kombat gamers

Prior to now few months, the Telegram clicker recreation Hamster Kombat has taken the world of cryptocurrency recreation lovers by storm. Regardless that the gameplay, which largely entails repeatedly tapping the display screen of 1’s cellular system, is likely to be slightly easy, gamers are after one thing extra: the potential for incomes large as soon as Hamster Kombat’s creators unveil the promised new cryptocoin tied to the sport.

On account of its success, the sport has already attracted numerous copycats that replicate its title and icon, and have comparable gameplay. Fortunately, all of the early examples we discovered weren’t malicious, however nonetheless goal to earn money from in-app ads.

Sadly, ESET researchers found that cybercriminals have additionally began to capitalize on Hamster Kombat’s reputation. Exposing the dangers of attempting to acquire video games and associated software program from unofficial sources, we discovered a number of threats abusing Hamster Kombat’s fame in such locations as remotely managed Android malware distributed by an unofficial Hamster Kombat Telegram channel, faux app shops that ship undesirable ads, and GitHub repositories distributing Lumma Stealer for Home windows gadgets whereas claiming to supply automation instruments for the sport.

Key factors of the blogpost:

• Hamster Kombat’s success has attracted malicious actors attempting to abuse curiosity within the recreation for financial acquire.
• ESET researchers found Android spy ware named Ratel pretending to be Hamster Kombat, distributed by way of an unofficial Telegram channel.
• Android customers are additionally focused by faux app shops claiming to supply the sport however delivering undesirable ads as an alternative.
• Home windows customers can encounter GitHub repositories providing farm bots and auto clickers that really include Lumma Stealer cryptors.

What’s Hamster Kombat?

Hamster Kombat is an in-app Telegram clicker recreation the place the gamers earn fictional foreign money by finishing easy duties, with incentives to log into the sport at the very least every day. As in different cellular clicker video games, the fundamental gameplay of Hamster Kombat includes tapping the display screen repeatedly to attain extra in-game factors. A screenshot illustrating the sport’s interface might be seen in Determine 1.

Launched in March 2024, Hamster Kombat appears to be gaining in reputation fairly shortly. In June 2024, the builders claimed that their recreation had already managed to succeed in 150 million energetic customers. Seeing as this is able to put Hamster Kombat – a recreation aimed simply on the cryptocurrency fanatic subset of cellular avid gamers, and obtainable solely by Telegram – within the high 20 most-played cellular video games of all time, the declare needs to be taken with a grain of salt. However, the sport is undoubtedly widespread: the official Hamster Kombat account on X has greater than 10 million followers, and the Hamster Kombat Announcement channel has greater than 50 million subscribers as of the publication of this blogpost.

Unsurprisingly, the primary purpose behind the quickly rising curiosity in Hamster Kombat is the gamers’ need to earn cash by enjoying the sport: Hamster Kombat’s improvement roadmap consists of plans for launching a brand new cryptocoin token tied to the sport. The token ought to subsequently be distributed to the gamers based mostly on assembly sure standards, a way also referred to as an airdrop.

The staff behind Hamster Kombat appears to be attempting to duplicate the success of one other Telegram-based recreation referred to as Notcoin, which in Might 2024 launched the NOT token on Telegram’s blockchain platform The Open Community (TON) and airdropped it to the gamers based mostly on their in-game scores. NOT token’s launch was very profitable, with some claiming it was the most important crypto-gaming-token launch of 2024 thus far.

The Hamster Kombat token drop can be supposed to make use of the TON community. Versus Notcoin, nonetheless, the variety of tokens obtained will not rely on complete rating however on different elements, equivalent to profit-per-hour.

Menace evaluation

As any mission promising earnings for little effort, the sport itself can be on the radar of cybersecurity consultants and authorities officers, who’re warning of potential monetary dangers concerned in enjoying. Thus far, ESET has not seen any malicious exercise from the unique app.

Android threats

We recognized and analyzed two varieties of threats concentrating on Android customers: a malicious app that accommodates the Android spy ware Ratel and faux web sites that impersonate app retailer interfaces claiming to have Hamster Kombat obtainable for obtain.

Ratel spy ware

ESET researchers discovered a Telegram channel (https://t[.]me/hamster_easy) distributing Android spy ware, named Ratel, disguised as Hamster Kombat; see Determine 2.

This malware is able to stealing notifications and sending SMS messages. The malware operators use this performance to pay for subscriptions and providers with the sufferer’s funds with out the sufferer noticing.

Whereas the malicious app misuses the title Hamster Kombat to draw potential victims, it accommodates no performance discovered inside the recreation and even lacks a person interface altogether. As displayed in Determine 3, upon startup, the app requests notification entry permission, and asks to be set because the default SMS software. As soon as these permissions are granted, the malware will get entry to all SMS messages and is ready to intercept all displayed notifications.

Ratel then initiates communication with its C&C server (http://77.91.124[.]14:260), and as a response, receives a cellphone quantity: see Determine 4. Afterwards, it sends an SMS message with the textual content Привет! Набери мне: logID (translation: Hey! Name me) to the that cellphone quantity, which probably belongs to the malware operators.

The menace actors then change into able to controlling the compromised system by way of SMS: the operator message can include a textual content to be despatched to a specified quantity, and even instruct the system to name the quantity. The malware can be in a position to test the sufferer’s present banking account steadiness for Sberbank Russia by sending a message with the textual content баланс (translation: steadiness) to the quantity 900. That is most likely finished with the intention to determine whether or not the operators ought to pursue additional assault situations to entry the sufferer’s funds.

Ratel additionally abuses notification entry permissions to cover notifications from over 200 apps based mostly on a hardcoded record (see the Appendix for the whole record). The record accommodates apps equivalent to Telegram, WhatsApp, and a number of other SMS messaging apps. If the affected system receives a notification from an app on the record, the sufferer won’t be able to see it. Hiding is the one motion the malware does with these notifications; they don’t seem to be forwarded to the C&C server. Most probably, the aim of intercepting the notifications is to forestall the sufferer from discovering affirmation messages despatched by subscription providers.

As proven in Determine 5, in case there’s a notification from an app not included within the record, Ratel lets the person see it, whereas additionally forwarding it to the C&C server. We expect this is likely to be finished in order that the operators can test whether or not a brand new app must be added to the record.

Faux web sites

Apart from the app with the Ratel spy ware, we additionally found faux software storefronts claiming to supply Hamster Kombat for obtain. Nevertheless, tapping the Set up or Open buttons solely leads the person to undesirable ads. Examples of the faux web sites might be present in Determine 6.

Home windows threats

Regardless that Hamster Kombat is a cellular recreation, we additionally discovered malware abusing the sport’s title to unfold on Home windows. Cybercriminals attempt to entice Home windows customers with auxiliary instruments that declare to make maximizing in-game earnings simpler for the gamers. Our analysis revealed GitHub repositories (see Determine 7) providing Hamster Kombat farm bots and autoclickers, that are instruments that automate clicks in a recreation. These repositories really turned out to hide cryptors from the notorious Lumma Stealer malware.

Lumma Stealer is an infostealer supplied as malware-as-a-service, obtainable for buy on the darkish internet and on Telegram. First noticed in 2022, this malware is usually distributed by way of pirated software program and spam, and targets cryptocurrency wallets, person credentials, two-factor authentication browser extensions, and different delicate info. Notice that Lumma Stealer’s capabilities aren’t lined by the MITRE ATT&CK matrix on this blogpost, for the reason that focus is on the cryptors that ship this infostealer, not on the infostealer itself.

The GitHub repositories we discovered both had the malware obtainable instantly within the launch recordsdata, or contained hyperlinks to obtain it from exterior file-sharing providers. We recognized three totally different variations of Lumma Stealer cryptors lurking inside the repositories: C++ purposes, Go purposes, and Python purposes. Of the three, solely the Python purposes have a graphical person interface (GUI).

C++ purposes

Within the case of the C++ purposes, Lumma Stealer is encrypted by way of the RC4 cipher and embedded within the executable the sufferer downloads. As soon as executed, the applying injects Lumma Stealer into the newly created course of C:WindowsMicrosoft.NETFrameworkv4.0.30319RegAsm.exe.

Go purposes

For the Go purposes, Lumma Stealer can be embedded within the executable, however this time, it’s encrypted utilizing AES-GCM. The cryptor makes use of copied and obfuscated code from go_libpeconv, a Go library for loading PE recordsdata, to do course of hollowing on the primary file discovered with the .exe extension underneath the C:Home windows listing.

Python purposes

The Python purposes had been both bundled with PyInstaller or compiled with Nuitka. When the sufferer runs the file downloaded from the GitHub repository, a faux installer window with an I agree button seems, as might be seen in Determine 8. Upon clicking the button, this system connects to an FTP server and downloads a password-protected ZIP archive (password: crypto123) containing the cryptor with Lumma Stealer embedded. We discovered C++ and Go cryptors on the FTP server, which leads us to the conclusion that these purposes are most likely totally different variations of the identical malware household.

As soon as the window is closed, the cryptor sends the C&C server the timestamps of when the sufferer clicked on the I agree button and when the malware was run. This information is shipped solely as soon as and there’s no additional C&C communication involving the cryptor. As proven in Determine 9, we discovered a remark report back to telegramm [sic] within the Python supply code of the malware, that means that most likely the information is shipped from the C&C to the operators’ Telegram account or channel in some unspecified time in the future.

Conclusion

Hamster Kombat’s reputation makes it ripe for abuse, which signifies that it’s extremely possible that the sport will appeal to extra malicious actors sooner or later. Whereas many copycat Hamster Kombat apps seem like malware-free, we found a remotely managed trojan distributed by way of Telegram disguised as the sport. The malware is able to sending SMS messages, making calls, and concealing its actions by hiding notifications that may recommend the system is compromised. Aside from the Android trojan, we additionally discovered faux app shops claiming to supply Hamster Kombat for obtain; the hyperlinks, nonetheless, usually result in undesirable ads. Lastly, on the Home windows platform, we uncovered GitHub repositories that lure avid gamers in with the promise of Hamster Kombat farm bots and autoclickers however that, in actuality, serve the victims with cryptors containing Lumma Stealer.

Because of Anton Cherepanov for his contributions.

For any inquiries about our analysis revealed on WeLiveSecurity, please contact us at threatintel@eset.com

ESET Analysis affords personal APT intelligence studies and information feeds. For any inquiries about this service, go to the ESET Menace Intelligence web page.

IoCs

A complete record of Indicators of Compromise (IoCs) and samples might be present in our GitHub repository.

Recordsdata

Community

Code-signing certificates

MITRE ATT&CK methods

This desk was constructed utilizing model 15 of the MITRE ATT&CK cellular methods.

This desk was constructed utilizing model 15 of the MITRE ATT&CK cellular methods.

Appendix

Following is the record of purposes from which the Ratel malware hides notifications: