New research shows that the bullies are most likely to be girls in the same year but in a different class to their victim.
The study comes after the deaths of three young girls were linked to online bullying.
It says that victims are more likely to be bullied by a single female or small group of females and the anonymity of the bullying online is extremely dangerous.
The research covered four categories of cyberbullying: text, picture or video clip, phone calls and emails. It found that the most common form was phone calls and text messages.
Teenagers who took part in the exercise by NUI Maynooth felt that all forms of cyberbullying other than bullying over email was worse than traditional bullying, with phone calls and the use of pictures or video being regarded as the most feared.
According to teenagers, cyberbullying was seen as worse than traditional bullying because there was no escape from it.
They also said that cyberbullying could be seen by more people and is unlikely to be noticed by an adult.
The topic has repeatedly made national headlines in recent months after the deaths of Ciara Pugsley (15), Erin Gallagher (13) and Lara Burns Gibbs (12).
Ciara, from Co Leitrim, took her own life in September and Donegal student Erin Gallagher (13) killed herself last month.
The death of Lara Burns Gibbs in Kilcock, Co Kildare, has also been linked to bullying, although sources close to her family say they do not know why she took her own life.
The study, among Irish second-level school pupils aged 12 to 18, found cyberbullying usually goes on for one to two weeks -- but in some cases it can last for several years.
It found that 17pc of children had been victims of bullying and a quarter of victims did not confide in anyone.
One in ten of the students who took part in the study admitted to being bullies themselves.
The report also coincides with the young age of the suicide victims and says that victims of bullying were more likely to be younger (30pc) than older (10pc), according to the students who took part in the research.
The research was carried out with a group of pupils in two co-educational schools who were asked a range of questions about cyberbullying.
Some 21pc of the students who took part in the study said that they had been victims of traditional bullying during the six months before the research.
There was no significant relationship between cyberbullying and issues such as family circumstances or time spent by teenagers using the internet or mobile phones, the study showed.
The research found that cyberbullying in rural schools was generally lower than those found in studies elsewhere, which typically reported rates of 25-35pc for victims of bullying.
The study was limited to only certain types of bullying, meaning that incidence of cyberbullying could be much higher.
The study did not cover websites, chatrooms and instant messages, partly because of the time required to complete the research.