In a report Tuesday it said Zalo was the top application with 26.37 percent of children using it, far ahead of second placed YouTube with 16.3 percent.
Tiktok accounted for 11.24 percent, followed by Facebook with 10 percent.
Kaspersky reviewed anonymized data, such as search queries, the most popular Android applications, and website categories provided voluntarily by Kaspersky Safe Kids users.
It said the data would help parents better understand their children's favorite subjects and passions.
Internationally, the most favorite apps were YouTube (31.6 percent of users), Tiktok (19 percent), WhatsApp (18 percent) and Roblox, an online game platform and game creation system.
According to German market and consumer data company Statista, the number of mobile Internet users in Vietnam in 2021 was an estimated 71.54 million and the number is expected to rise to 82.15 million by 2025.