Why is the FBI asking you to restart (or replace) your router?

https://www.avg.com/en/signal/vpnfilter-router-malware-quick-fix?et_cid=144276&et_rid=66020015&ecid=con_oo_pc_alac_all_all_2018_q2_bojj_news06&mailing=con_oo_pc_alac_all_all_2018_q2_bojj_news06&utm_medium=email&utm_source=sfmc&utm_campaign=con_oo_pc_alac_all_all_2018_q2_bojj_news06&utm_content=