The South’s National Intelligence Service (NIS) said in a report to parliament last week that North Korea attempted to hack more than 20,000 South Korean smartphones from May to September.
The agency said it had worked with the owners of South Korean websites and government officials to remove the applications and block relevant hacking channels.
Pyongyang’s official Internet news provider Uriminzokkiri accused the NIS of fabricating the report to distract public attention from a stand-off over South Korean activists sending leaflets critical of the North’s regime across the border in balloons.
“It’s (the) usual tactic used by South Korean authorities to fan anti-Pyongyang sentiment whenever they face a political crisis,” it said.
The two Koreas had decided earlier this month to restart high-level talks by early November.
South Korea had proposed meeting last week, but the North said the refusal to ban the balloon launches had soured the atmosphere and threatened any future meeting.
In recent years, hackers have deployed cyber-attacks on South Korean military institutions, commercial banks, government agencies, TV broadcasters and media websites.
Investigations into past large-scale cyber assaults have concluded that North Korea was the source.
The North is believed to run an elite cyber war unit of at least 3,000 personnel, but it has denied any involvement and accuses Seoul of fabricating the incidents to fan cross-border tensions.