Buen, who was named as a possible suspect in the "Love Bug" virus case together with his college friend, Onel De Guzman, said the program he created for his thesis was "entirely distinct and different from the 'ILOVEYOU' virus, and more importantly, was accepted by AMA as a legitimate program, not contrary to law."
"In an effort to restore some semblance of normalcy to my life and that of my family, I should like to categorically state for the record that I have no involvement or participation whatsoever in the design, development, creation or dissemination of the 'ILOVEYOU' virus," read a statement released by Buen to journalists.
The 23-year-old student denied that he had been hiding, but said he finally came out in public "to vindicate my good name and reputation."
"These allegations and insinuations have caused me and my family great distress," he added.
Buen's lawyer, Patrick Orosa, said Buen had already met with officials of the National Bureau of Investigation (NBI) but he declined to divulge details of the meeting. Buen has not received any summons to return to the NBI, added Orosa.
The National Bureau of Investigation (NBI) says it will finish its examination early this week of 17 computer diskettes seized from De Guzman's apartment.
NBI computer experts are already completing their investigation into the diskettes, according to Carlos Caabay, the NBI's deputy director for investigative services .
Although no charges have been filed against De Guzman, Caabay said they are investigating De Guzman's possible involvement in the case, as well as that of Buen and 10 members of the underground computer organisation Grammersoft.
This week the NBI is expected to begin filing formal charges after it gains what it considers sufficient evidence.
On Thursday, De Guzman finally came out of hiding and appeared at the NBI office together with his sister Irene and their lawyer, Rolando Quimbo.
Irene is the girlfriend of Reomel Ramones, the bank employee who earlier was arrested and released after 24 hours due to lack of evidence. Ramones has been charged with violating the Access Devices Regulation Act, a law against credit card and ATM (automated teller machine) fraud.
The preliminary hearing for the case against Ramones is scheduled on May 19.
De Guzman, who was in hiding for a week, refused to deny or confirm that he wrote the "Love Bug" virus, only saying that the answer would be known in the future.
But when asked if he might have accidentally spread the "Love Bug" virus, De Guzman: "It is possible."
Quimbo said De Guzman is not aware if he is actually responsible for the accusations hurled against him. "He doesn't know if these consequences could be the results of his work," said Quimbo.
On Wednesday, officials of AMACC and the NBI found "circumstantial evidence" linking De Guzman and Buen to the "Love Bug" virus.
In February, De Guzman wrote a software program, called Email Password Sender Trojan, that could send all the passwords in an infected computer to a specified email address. He submitted the program as his thesis proposal, a requirement for graduation, but it was immediately rejected by school authorities.
Manny Abad, executive vice president of the AMA Educational System, said they asked De Guzman to revise his thesis but he never did, and that is why he failed to graduate last month.
Buen's thesis, on the other hand, allowed users to save multiple copies, even "hundreds" of copies, of the same file using a single save command. School officials allowed Buen to graduate because his thesis was "legitimate".
The two were identified through user IDs provided by Sky Internet, the local Internet service provider used by the virus author to store and send virus files.
Ten other names or aliases have been submitted to the NBI, but authorities have not found the real identities of these suspects.
Karim Bancola, senior vice president of AMACC, surmised that if the two software programs written by De Guzman and Buen were integrated, they could produce effects similar to those caused by the "I Love You" virus.
The code for the virus could have started from the Philippines and been later changed or enhanced by other programmers in other countries, possibly by a German exchange student earlier identified by Swedish expert Fredrik Bjoerck, explained Bancola.
In his paper proposal, De Guzman wrote that Internet users were paying too much for Internet access so he wrote the program to allow people to "steal" passwords and gain free access.
Quimbo, however, said that De Guzman merely wanted school officials to use the program for future study.
"What he wanted was to present these possibilities to school authorities so that it can be used in future studies," said Quimbo.
De Guzman, who admitted that he was a member of Grammersoft, said that other members of the group had knowledge of his thesis.
Quimbo suggested that other people might have participated in creating the virus. "We can go as far as saying that he did prepare the thesis proposal, but the knowledge of its contents were not limited to one (person)," he said.
De Guzman said Buen is not a member of Grammersoft, contradicting earlier announcements by AMACC officials. The name of Grammersoft was found by computer experts in the code of the "Love Bug" virus.
Other members of Grammersoft, however, expressed doubts that De Guzman was capable of writing the "Love Bug" virus. "They don't have that much technical skills," said one member of the group, who asked not to be identified.
Grammersoft is not a recognised organisation at AMACC, Abad said.
The group writes software programs for small and medium-sized companies and sells thesis studies to computer students.