The faucet-estry of threats focusing on Hamster Kombat gamers

Up to now few months, the Telegram clicker sport Hamster Kombat has taken the world of cryptocurrency sport lovers by storm. Though 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 of incomes huge as soon as Hamster Kombat’s creators unveil the promised new cryptocoin tied to the sport.

Attributable to its success, the sport has already attracted numerous copycats that replicate its title and icon, and have related gameplay. Fortunately, all of the early examples we discovered weren’t malicious, however nonetheless intention to become profitable from in-app commercials.

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 commercials, and GitHub repositories distributing Lumma Stealer for Home windows units 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 sport for financial acquire.
• ESET researchers found Android adware named Ratel pretending to be Hamster Kombat, distributed through an unofficial Telegram channel.
• Android customers are additionally focused by faux app shops claiming to supply the sport however delivering undesirable commercials as a substitute.
• 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 sport the place the gamers earn fictional foreign money by finishing easy duties, with incentives to log into the sport no less than every day. As in different cellular clicker video games, the fundamental gameplay of Hamster Kombat entails tapping the display screen repeatedly to attain extra in-game factors. A screenshot illustrating the sport’s interface may 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 sport had already managed to achieve 150 million energetic customers. Seeing as this may put Hamster Kombat – a sport aimed simply on the cryptocurrency fanatic subset of cellular players, and obtainable solely by Telegram – within the high 20 most-played cellular video games of all time, the declare ought to be taken with a grain of salt. Nonetheless, the sport is undoubtedly well-liked: 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 principle motive behind the quickly rising curiosity in Hamster Kombat is the gamers’ want to earn cash by taking part in the sport: Hamster Kombat’s growth roadmap contains plans for launching a brand new cryptocoin token tied to the sport. The token ought to subsequently be distributed to the gamers primarily based on assembly sure standards, a method also referred to as an airdrop.

The group behind Hamster Kombat appears to be attempting to copy the success of one other Telegram-based sport referred to as Notcoin, which in Could 2024 launched the NOT token on Telegram’s blockchain platform The Open Community (TON) and airdropped it to the gamers primarily based 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 also 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, resembling profit-per-hour.

Menace evaluation

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

Android threats

We recognized and analyzed two kinds of threats focusing on Android customers: a malicious app that comprises the Android adware Ratel and faux web sites that impersonate app retailer interfaces claiming to have Hamster Kombat obtainable for obtain.

Ratel adware

ESET researchers discovered a Telegram channel (https://t[.]me/hamster_easy) distributing Android adware, 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 comprises no performance discovered inside the sport and even lacks a consumer interface altogether. As displayed in Determine 3, upon startup, the app requests notification entry permission, and asks to be set because the default SMS utility. 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 telephone quantity: see Determine 4. Afterwards, it sends an SMS message with the textual content Привет! Набери мне: logID (translation: Good day! Name me) to the that telephone quantity, which almost certainly belongs to the malware operators.

The risk actors then turn into able to controlling the compromised system through 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 also be capable of 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 likely achieved with a purpose to resolve 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 primarily based on a hardcoded listing (see the Appendix for the entire listing). The listing comprises apps resembling Telegram, WhatsApp, and several other SMS messaging apps. If the affected system receives a notification from an app on the listing, the sufferer will be unable 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. More than likely, the aim of intercepting the notifications is to stop 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 listing, Ratel lets the consumer see it, whereas additionally forwarding it to the C&C server. We expect this is likely to be achieved in order that the operators can test whether or not a brand new app must be added to the listing.

Faux web sites

Apart from the app with the Ratel adware, we additionally found faux utility storefronts claiming to supply Hamster Kombat for obtain. Nevertheless, tapping the Set up or Open buttons solely leads the consumer to undesirable commercials. Examples of the faux web sites may be present in Determine 6.

Home windows threats

Though Hamster Kombat is a cellular sport, 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 sport. These repositories truly turned out to hide cryptors from the notorious Lumma Stealer malware.

Lumma Stealer is an infostealer provided as malware-as-a-service, obtainable for buy on the darkish net and on Telegram. First noticed in 2022, this malware is often distributed through pirated software program and spam, and targets cryptocurrency wallets, consumer credentials, two-factor authentication browser extensions, and different delicate info. Notice that Lumma Stealer’s capabilities usually are not lined by the MITRE ATT&CK matrix on this blogpost, because the 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 information, or contained hyperlinks to obtain it from exterior file-sharing providers. We recognized three completely different variations of Lumma Stealer cryptors lurking inside the repositories: C++ functions, Go functions, and Python functions. Of the three, solely the Python functions have a graphical consumer interface (GUI).

C++ functions

Within the case of the C++ functions, Lumma Stealer is encrypted through 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 functions

For the Go functions, Lumma Stealer can also 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 information, to do course of hollowing on the primary file discovered with the .exe extension beneath the C:Home windows listing.

Python functions

The Python functions 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 may 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 functions are most likely completely 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 knowledge is distributed 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 info is distributed from the C&C to the operators’ Telegram account or channel sooner or later.

Conclusion

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

Due to Anton Cherepanov for his contributions.

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

ESET Analysis provides non-public APT intelligence reviews and knowledge feeds. For any inquiries about this service, go to the ESET Menace Intelligence web page.

IoCs

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

Information

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 listing of functions from which the Ratel malware hides notifications: