Spam text messages sent to smartphones and other mobile devices claiming to have information on the sunken Sewol ferry, have been spreading widely and hurting family members of the victims.
The government warned citizens not to download such SMS phishing, or "smishing," messages, which are aimed at extracting personal data.
It told the public to just delete false messages as they can embed malicious codes in mobile devices if their attached links are clicked on.
The government and police warned the senders of such ill-intended messages, saying those who try to take advantage of this tragic accident will be held accountable.
The Korea Communications Standards Commission, the state censorship body, also said it would delete slanderous Internet postings and comments against victims and their families, and cut off access to those spreading false information on the Internet.
Korean portal operators including Naver, Daum and Nate said they would beef up their monitoring systems to prevent Internet comments and postings that defame the victims and their families from spreading.
It was found out that one of the text messages purportedly sent from a survivor of the sunken Sewol ferry begging for help had actually been sent by a fifth grader.
Internet comments and postings with false information have gone viral, while groundless conspiracy theories concerning the ferry and its victims have become rampant.
Some Internet users posted incendiary political comments with links to adult websites, while others even argued that the latest accident took place as the Sewol ferry was trying to dodge a North Korean submarine.
The slew of comments also included claims that they were members of the rescue team and provided false updates regarding the ongoing search operations.
They have been spreading through social network platforms such as Facebook, Twitter and KakaoTalk.
Further, at the temporary shelter on Jindo Island, people who claimed to be divers asked for 100 million won ($96,000) from family members of the victims in return for recovering the bodies of those who remained inside the ferry.
The government additionally warned against those who disguised themselves as government officials from the Ministry of Education and tried to steal condolence funds from families holding funerals for those who died in the accident.