As of 2021, numerous users left WhatsApp for messaging to various other applications that promised improved data protection only after the company announced that it might default share user metadata with Facebook. Many of those users turned to Telegram and Signal, which proves to be the competitive applications against WhatsApp. 

As per Sensor Tower, Telegram was perhaps the most installed application with over 63 million downloads in January 2021. Telegram chatting is still not encoded as in Signal Chat end-to-end encryption is there, but now Telegram does have another issue: malware. 

Software Check Point team recently found that cybercriminals use Telegram for something like a malware program named Toxic Eye as a communications platform. It turns out that certain aspects of Telegram are much more readily accessible by attackers than it is by web-based tools. Today, they have handy Telegram Bots to mess up with compromised machines. 

Toxic Eye is a kind of malware known as a remote access trojan (RAT). RATs can remotely monitor an intruder over an infected machine, which means that the attacker could steal host computer data, destroy, or copy files, hamper the operations of an infected machine, and much more. The Toxic Eye RAT is distributed through an e-mail with an encoded EXE file to a destination. The software installs the malware on the user computer if the target users access the file. 

RATs are comparable to programs of remote access and can be used to control user devices, for instance, by someone in technical support. However, even without authorization, these programs sneak in. They could imitate or hide with legitimate files that sometimes are concealed as a document or are inserted in a broader video game file. 

Attackers used Telegram to remotely manipulate malicious software. Check Point analyst Omer Hofman claims that from February until April 2021 the company found 130 Toxic Eye attacks with this tool, and some items make Telegram valuable to bad players who distribute malware. 

The firewall program doesn't obstruct Telegram. The network control tools are also not blocked. It's a user-friendly app that most people recognize as genuine, then let their guards down. 

The researcher's advice is that one must not access email attachments from unidentified senders, which raises suspicion. Also, take care of appendices containing usernames. Malicious emails also contain the username or an attachment title in the subject line. It is possibly malicious if the sender attempts to sound urgent, dangerous, or compulsive and forces the user to click upon a link or attachment or to provide sensitive data. If possible, then one must use anti-phishing tools.