According to the University of Manchester, hackers are thought to have copied a "small proportion" of data pertaining to a select group of its students and graduates during a cyberattack.
On June 6, "an unauthorized party" "accessed by an unauthorised party" some of the university's systems.
If the university did not comply, the email threatened to sell private information on the black market.
The university claimed to have reached out to those affected.
In a statement, the institution, which has 12,000 staff members and about 40,000 students, said: "We understand that this will cause concern for some, but we would like to reassure our community that our internal and external experts are working around the clock to continue to address this and our investigations are continuing.
"We are requesting that all staff members and students be on the lookout for any suspicious emails, including those that might appear to be sent by the individuals accountable for this incident.
Do not respond to these emails in any way or interact with them.
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