TikTok, the short-video sensation that¡¯s among the world¡¯s most downloaded apps, is coming under increased scrutiny about its data security as it guards the personal information of over a billion users.

On Monday, several cybersecurity analysts tweeted about the discovery of what was purportedly a breach of an insecure server that allowed access to TikTok¡¯s storage, which they believe contained personal user data. Only days earlier, Microsoft Corp. said it had found a ¡°high-severity vulnerability¡± in TikTok¡¯s Android application, ¡°which would have allowed attackers to compromise users¡¯ accounts with a single click.¡±

ByteDance Ltd.¡¯s TikTok surpassed a billion monthly users a year ago and now ranks as many young people¡¯s favorite app. That makes it an enticing target for hackers who may seek to hijack popular accounts or resell sensitive information. It was identified as a privacy threat by the administration of then-U.S. President Donald Trump in 2020 and nearly banned because of concern about potential links between its Beijing-based parent company and the Chinese government.