Steam appearing in Russian can happen due to a few common reasons:

• Steam's language settings may have been changed accidentally or by a glitch. This can happen after password changes or other account modifications, causing the UI to switch language unexpectedly to Russian or other languages. The language can be manually changed back in settings.

• Sometimes, if Steam detects that the user is connecting from a Russian IP address or region, it may default to Russian for localized content or games. This is part of region locking or localization policies to restrict versions and prices by region.

• Another potential cause is account hacking or malware, where unauthorized access switches the language and account info, often requiring password changes and security checks.

• Finally, it could be a temporary bug or glitch in the Steam client’s language detection system.

In summary, Steam being in Russian usually relates to language settings, region detection, or security issues. The language can be changed back in Steam's settings menu under language preferences, or users should check their account's security if they did not make the change themselves.

If the language persists unexpectedly, checking IP region settings, using VPNs carefully, or contacting Steam support is advisable.