"We can confirm that incidents occurred last year where we dealt with computer hacking that was carried out by foreign intelligence services," Fredrik Wallin, spokesman from Sweden's National Defence Radio Establishment (Försvarets radioanstalt - FRA) told the Dagens Nyheter (DN) newspaper on Wednesday.
FRA, along with Sweden's Civil Contingencies Agency (Myndigheten för samhällsskydd och beredskap - MSB), participate in a national cyber-defence project to analyze and assess IT threats to Sweden's national security.
Last year, several advanced attacks took place, ranging from attempts to gain unauthorized access to computer and IT systems, to full-blown hacker attacks.
"They choose a person and try to plant malicious code in their computer so they can monitor them and steal information," MSB IT security expert Jonas Thambert told the paper.
Public agency heads, the CEOs and CFOs of listed companies, and defence industry researchers are among those often targeted for the attacks, he added. Using their own signals intelligence methods, FRA has been able to trace the attacks to foreign intelligence agencies.
FRA spokesman Wallin warned the attacks "undermine Sweden's competitiveness as a nation".
Recently, FRA made headlines for revelations about its cooperation with the US National Security Agency (NSA) contained in documents leaked by whistleblower Edward Snowden. The documents indicated that FRA worked with the NSA in operations to hack into computers and carry out internet surveillance on Swedes. In addition, the documents reveal that Sweden spied on Russia for the NSA.