Security experts from Kaspersky have discovered a backdoor account and other three vulnerabilities in D-Link DIR-620 Routers. The flawed devices were distributed by ISPs in Russia, CIS, and Eastern Europe ISPs (most of them in Russia) The only way to mitigate the issue is to avoid exposing the admin panel online. D-link was notified the vulnerabilities by said it will not issue firmware updates to address them. The remaining issues are: Hardcoded default credentials for Telnet and OS command injection (reflected cross-site scripting)”]
Source: https://securityaffairs.co/wordpress/72839/hacking/d-link-dir-620-flaws.html