Some MailChimp customers had their accounts hijacked, with the end result that their newsletter subscribers received a malicious email. A security researcher had a database of over 2,000 usernames and passwords. The data was a small part of a larger data haul collected by the Vawtrak password-stealing trojan. Vawtra is a notorious piece of malware often spread via malicious Word documents which can spy on its victims by logging keystrokes, taking screenshots and hijacking webcams.”]
Source: https://grahamcluley.com/just-mailchimp-accounts-hacked/