Young scientist from the University of Tartu catching Skype scammers | University of Tartu
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Faculty of Arts and Humanities
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(+372) 737 5341
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Jakobi 2 - 116-121, 51014, Tartu
  • Dean's Office
    Faculty phone: 
    + 372 737 5341
    Faculty address: 
    Jakobi 2, rooms 116 - 121, 51014, Tartu
  • Institute of History and Archaeology
    Faculty phone: 
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    Faculty address: 
    Jakobi 2, 51003, Tartu
  • Institute of Estonian and General Linguistics
    Faculty phone: 
    (+372) 737 5221
    Faculty address: 
    Jakobi 2, 51014, Tartu
  • Institute of Philosophy and Semiotics
    Faculty phone: 
    (+372) 737 5314
    Faculty address: 
    Jakobi 2, III, rooms 309-352, 51014, Tartu
  • Institute of Cultural Research
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    Faculty address: 
    Ülikooli 16, 51003, Tartu
  • School of Theology and Religious Studies
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    (+372) 737 5301
    Faculty address: 
    Ülikooli 18-310, 50090, Tartu
  • College of Foreign Languages and Cultures
    Faculty address: 
    Lossi 3, 51003, Tartu
  • Viljandi Culture Academy
    Faculty phone: 
    (+372) 435 5232
    Faculty address: 
    Posti 1, 71004, Viljandi
Faculty of Social Sciences
Faculty phone: 
(+372) 737 5957
Faculty address: 
Lossi 36, 51003, Tartu
  • Dean's Office
    Faculty phone: 
    + 372 737 5900
    Faculty address: 
    Lossi 36, 51003, Tartu
  • Institute of Education
    Faculty phone: 
    (+372) 737 6440
    Faculty address: 
    Salme 1a, room 29, 50103, Tartu
  • Johan Skytte Institute of Political Studies
    Faculty phone: 
    (+372) 737 5582
    Faculty address: 
    Lossi 36, roomm 301, 51003, Tartu
  • School of Economics and Business Administration
    Faculty phone: 
    (+372) 737 6310
    Faculty address: 
    J. Liivi 4, 50409, Tartu
  • Institute of Psychology
    Faculty phone: 
    (+372) 737 5902
    Faculty address: 
    Näituse 2, 50409, Tartu
  • School of Law
    Faculty phone: 
    (+372) 737 5390
    Faculty address: 
    Näituse 20, 50409, Tartu
  • Institute of Social Studies
    Faculty phone: 
    (+372) 737 5188
    Faculty address: 
    Lossi 36, 51003, Tartu
  • Narva College
    Faculty phone: 
    (+372) 740 1900
    Faculty address: 
    Raekoja plats 2, 20307, Narva
  • Pärnu College
    Faculty phone: 
    (+372) 445 0520
    Faculty address: 
    Ringi 35, 80012, Pärnu
Faculty of Medicine
Faculty phone: 
(+372) 737 5326
Faculty address: 
Ravila 19, 50411, Tartu
  • Dean's Office
    Faculty phone: 
    (+372) 737 5326
    Faculty address: 
    Ravila 19, 50411, Tartu
  • Institute of Biomedicine and Translational Medicine
    Faculty phone: 
    +(372) 737 4210
    Faculty address: 
    Biomeedikum, Ravila 19, 50411, Tartu
  • Institute of Pharmacy
    Faculty phone: 
    (+372) 737 5286
    Faculty address: 
    Nooruse 1, 50411, Tartu
  • Institute of Dentistry
    Faculty phone: 
    (+372) 731 9856
    Faculty address: 
    Raekoja plats 6, 51003, Tartu
  • Institute of Clinical Medicine
    Faculty phone: 
    (+372) 737 5323
    Faculty address: 
    L. Puusepa 8, 51014, Tartu, Eesti
  • Institute of Family Medicine and Public Health
    Faculty phone: 
    (+372) 737 4190
    Faculty address: 
    Ravila 19, 50411 Tartu
  • Institute of Sport Sciences and Physiotherapy
    Faculty phone: 
    (+372) 737 5360
    Faculty address: 
    Jakobi 5-205, 51014, Tartu
Faculty of Science and Technology
Faculty phone: 
(+372) 737 5820
Faculty address: 
Vanemuise 46-208, 51014, Tartu
  • Dean's Office
    Faculty phone: 
    (+372) 737 5820
    Faculty address: 
    Vanemuise 46 - 208, 51014, Tartu
  • Institute of Computer Science
    Faculty phone: 
    (+372) 737 5445
    Faculty address: 
    J. Liivi 2, 50409, Tartu
  • Estonian Marine Institute
    Faculty phone: 
    (+372) 671 8902
    Faculty address: 
    Mäealuse 14, 12618, Tallinn
  • Institute of Physics
    Faculty address: 
    W. Ostwaldi Str 1, 50411, Tartu
  • Institute of Chemistry
    Faculty phone: 
    (+372) 737 5261
    Faculty address: 
    Ravila 14a, 50411, Tartu
  • Institute of Mathematics and Statistics
    Faculty phone: 
    (+372) 737 5860
    Faculty address: 
    J. Liivi 2, 50409, Tartu
  • Institute of Molecular and Cell Biology
    Faculty phone: 
    (+372) 737 5011
    Faculty address: 
    Riia 23, 23b-134, 51010, Tartu
  • Institute of Technology
    Faculty phone: 
    (+372) 737 4800
    Faculty address: 
    Nooruse 1, 50411, Tartu
  • Institute of Ecology and Earth Sciences
    Faculty phone: 
    (+372) 737 5835
    Faculty address: 
    Vanemuise 46, 51014, Tartu
Institutions
  • Library
    Faculty phone: 
    (+372) 737 5702
    Faculty address: 
    W.Struve 1, 50091, Tartu
  • Youth Academy
    Faculty phone: 
    (+372) 737 5581
    Faculty address: 
    Lossi 38, 51003, Tartu
  • Estonian Genome Center
    Faculty phone: 
    (+372) 737 4000
    Faculty address: 
    Riia 23b, 51010, Tartu
  • Museum
    Faculty phone: 
    (+372) 737 5674
    Faculty address: 
    Lossi 25, 51014, Tartu
  • University of Tartu Natural History Museum and Botanical Garden
    Faculty phone: 
    (+372) 737 6076
    Faculty address: 
    Vanemuise 46, 51014, Tartu
Support Units
  • Administrative Office
    Faculty phone: 
    (+372) 737 5606
    Faculty address: 
    Ülikooli 18a, 51014, Tartu
  • University Office in Tallinn
    Faculty phone: 
    +372 737 6600
    Faculty address: 
    Teatri väljak 3, 10143 Tallinn
  • Estates Office
    Faculty phone: 
    (+372) 737 5137
    Faculty address: 
    Ülikooli 18a, 51014, Tartu
  • Finance Office
    Faculty phone: 
    (+372) 737 5125
    Faculty address: 
    Jakobi 4, 51014, Tartu
  • Information Technology Office
    Faculty phone: 
    (+372) 737 6000, arvutiabi: 737 5500
    Faculty address: 
    Ülikooli 18a, 51014, Tartu
  • Internal Audit Office
    Faculty address: 
    Ülikooli 17-114, 51014, Tartu
  • Marketing and Communication Office
    Faculty phone: 
    (+372) 737 5687
    Faculty address: 
    Ülikooli 18, ruum 210, 50090, Tartu
  • Office of Academic Affairs
    Faculty phone: 
    (+372) 737 6215
    Faculty address: 
    Ülikooli 18, 50090, Tartu
  • Office of Research and Development
    Faculty phone: 
    (+372) 737 6192
    Faculty address: 
    Lossi 3, III korrus, 51003, Tartu
  • Human Resources Office
    Faculty phone: 
    (+372) 737 5145
    Faculty address: 
    Ülikooli 18, rooms 302 and 304, 50090, Tartu
  • Rector's Strategy Office
    Faculty phone: 
    (+372) 737 5600
    Faculty address: 
    Ülikooli 18, 51014, Tartu
  • Student Council
    Faculty phone: 
    (+372) 737 5400
    Faculty address: 
    Ülikooli 18b, 51014, Tartu
Other Units
  • University of Tartu Academic Sports Club
    Faculty phone: 
    +372 737 5371
    Faculty address: 
    Ujula 4, 51008 Tartu
  • Tartu Student Village
    Faculty phone: 
    +372 740 9959
    Faculty address: 
    Narva mnt 25, 51013 Tartu
  • Tartu Students’ Club
    Faculty phone: 
    +372 730 2400
    Faculty address: 
    Kalevi 24, 51010 Tartu
  • University of Tartu Press
    Faculty phone: 
    +372 737 5945
    Faculty address: 
    W. Struve 1, 50091 Tartu
  • Tartu University Hospital
    Faculty address: 
    L. Puusepa 1a, 50406 Tartu
  • University of Tartu Foundation
    Faculty phone: 
    +372 737 5852
    Faculty address: 
    Ülikooli 18, 50090 Tartu
  • View all other units

Contacts of UT units

Faculty of Arts and Humanities
Faculty phone: 
(+372) 737 5341
Faculty address: 
Jakobi 2 - 116-121, 51014, Tartu
  • Dean's Office
    Faculty phone: 
    + 372 737 5341
    Faculty address: 
    Jakobi 2, rooms 116 - 121, 51014, Tartu
  • Institute of History and Archaeology
    Faculty phone: 
    (+372) 737 5651
    Faculty address: 
    Jakobi 2, 51003, Tartu
  • Institute of Estonian and General Linguistics
    Faculty phone: 
    (+372) 737 5221
    Faculty address: 
    Jakobi 2, 51014, Tartu
  • Institute of Philosophy and Semiotics
    Faculty phone: 
    (+372) 737 5314
    Faculty address: 
    Jakobi 2, III, rooms 309-352, 51014, Tartu
  • Institute of Cultural Research
    Faculty phone: 
    (+372) 737 5223
    Faculty address: 
    Ülikooli 16, 51003, Tartu
  • School of Theology and Religious Studies
    Faculty phone: 
    (+372) 737 5301
    Faculty address: 
    Ülikooli 18-310, 50090, Tartu
  • College of Foreign Languages and Cultures
    Faculty address: 
    Lossi 3, 51003, Tartu
  • Viljandi Culture Academy
    Faculty phone: 
    (+372) 435 5232
    Faculty address: 
    Posti 1, 71004, Viljandi
Faculty of Social Sciences
Faculty phone: 
(+372) 737 5957
Faculty address: 
Lossi 36, 51003, Tartu
  • Dean's Office
    Faculty phone: 
    + 372 737 5900
    Faculty address: 
    Lossi 36, 51003, Tartu
  • Institute of Education
    Faculty phone: 
    (+372) 737 6440
    Faculty address: 
    Salme 1a, room 29, 50103, Tartu
  • Johan Skytte Institute of Political Studies
    Faculty phone: 
    (+372) 737 5582
    Faculty address: 
    Lossi 36, roomm 301, 51003, Tartu
  • School of Economics and Business Administration
    Faculty phone: 
    (+372) 737 6310
    Faculty address: 
    J. Liivi 4, 50409, Tartu
  • Institute of Psychology
    Faculty phone: 
    (+372) 737 5902
    Faculty address: 
    Näituse 2, 50409, Tartu
  • School of Law
    Faculty phone: 
    (+372) 737 5390
    Faculty address: 
    Näituse 20, 50409, Tartu
  • Institute of Social Studies
    Faculty phone: 
    (+372) 737 5188
    Faculty address: 
    Lossi 36, 51003, Tartu
  • Narva College
    Faculty phone: 
    (+372) 740 1900
    Faculty address: 
    Raekoja plats 2, 20307, Narva
  • Pärnu College
    Faculty phone: 
    (+372) 445 0520
    Faculty address: 
    Ringi 35, 80012, Pärnu
Faculty of Medicine
Faculty phone: 
(+372) 737 5326
Faculty address: 
Ravila 19, 50411, Tartu
  • Dean's Office
    Faculty phone: 
    (+372) 737 5326
    Faculty address: 
    Ravila 19, 50411, Tartu
  • Institute of Biomedicine and Translational Medicine
    Faculty phone: 
    +(372) 737 4210
    Faculty address: 
    Biomeedikum, Ravila 19, 50411, Tartu
  • Institute of Pharmacy
    Faculty phone: 
    (+372) 737 5286
    Faculty address: 
    Nooruse 1, 50411, Tartu
  • Institute of Dentistry
    Faculty phone: 
    (+372) 731 9856
    Faculty address: 
    Raekoja plats 6, 51003, Tartu
  • Institute of Clinical Medicine
    Faculty phone: 
    (+372) 737 5323
    Faculty address: 
    L. Puusepa 8, 51014, Tartu, Eesti
  • Institute of Family Medicine and Public Health
    Faculty phone: 
    (+372) 737 4190
    Faculty address: 
    Ravila 19, 50411 Tartu
  • Institute of Sport Sciences and Physiotherapy
    Faculty phone: 
    (+372) 737 5360
    Faculty address: 
    Jakobi 5-205, 51014, Tartu
Faculty of Science and Technology
Faculty phone: 
(+372) 737 5820
Faculty address: 
Vanemuise 46-208, 51014, Tartu
  • Dean's Office
    Faculty phone: 
    (+372) 737 5820
    Faculty address: 
    Vanemuise 46 - 208, 51014, Tartu
  • Institute of Computer Science
    Faculty phone: 
    (+372) 737 5445
    Faculty address: 
    J. Liivi 2, 50409, Tartu
  • Estonian Marine Institute
    Faculty phone: 
    (+372) 671 8902
    Faculty address: 
    Mäealuse 14, 12618, Tallinn
  • Institute of Physics
    Faculty address: 
    W. Ostwaldi Str 1, 50411, Tartu
  • Institute of Chemistry
    Faculty phone: 
    (+372) 737 5261
    Faculty address: 
    Ravila 14a, 50411, Tartu
  • Institute of Mathematics and Statistics
    Faculty phone: 
    (+372) 737 5860
    Faculty address: 
    J. Liivi 2, 50409, Tartu
  • Institute of Molecular and Cell Biology
    Faculty phone: 
    (+372) 737 5011
    Faculty address: 
    Riia 23, 23b-134, 51010, Tartu
  • Institute of Technology
    Faculty phone: 
    (+372) 737 4800
    Faculty address: 
    Nooruse 1, 50411, Tartu
  • Institute of Ecology and Earth Sciences
    Faculty phone: 
    (+372) 737 5835
    Faculty address: 
    Vanemuise 46, 51014, Tartu
Institutions
  • Library
    Faculty phone: 
    (+372) 737 5702
    Faculty address: 
    W.Struve 1, 50091, Tartu
  • Youth Academy
    Faculty phone: 
    (+372) 737 5581
    Faculty address: 
    Lossi 38, 51003, Tartu
  • Estonian Genome Center
    Faculty phone: 
    (+372) 737 4000
    Faculty address: 
    Riia 23b, 51010, Tartu
  • Museum
    Faculty phone: 
    (+372) 737 5674
    Faculty address: 
    Lossi 25, 51014, Tartu
  • University of Tartu Natural History Museum and Botanical Garden
    Faculty phone: 
    (+372) 737 6076
    Faculty address: 
    Vanemuise 46, 51014, Tartu
Support Units
  • Administrative Office
    Faculty phone: 
    (+372) 737 5606
    Faculty address: 
    Ülikooli 18a, 51014, Tartu
  • University Office in Tallinn
    Faculty phone: 
    +372 737 6600
    Faculty address: 
    Teatri väljak 3, 10143 Tallinn
  • Estates Office
    Faculty phone: 
    (+372) 737 5137
    Faculty address: 
    Ülikooli 18a, 51014, Tartu
  • Finance Office
    Faculty phone: 
    (+372) 737 5125
    Faculty address: 
    Jakobi 4, 51014, Tartu
  • Information Technology Office
    Faculty phone: 
    (+372) 737 6000, arvutiabi: 737 5500
    Faculty address: 
    Ülikooli 18a, 51014, Tartu
  • Internal Audit Office
    Faculty address: 
    Ülikooli 17-114, 51014, Tartu
  • Marketing and Communication Office
    Faculty phone: 
    (+372) 737 5687
    Faculty address: 
    Ülikooli 18, ruum 210, 50090, Tartu
  • Office of Academic Affairs
    Faculty phone: 
    (+372) 737 6215
    Faculty address: 
    Ülikooli 18, 50090, Tartu
  • Office of Research and Development
    Faculty phone: 
    (+372) 737 6192
    Faculty address: 
    Lossi 3, III korrus, 51003, Tartu
  • Human Resources Office
    Faculty phone: 
    (+372) 737 5145
    Faculty address: 
    Ülikooli 18, rooms 302 and 304, 50090, Tartu
  • Rector's Strategy Office
    Faculty phone: 
    (+372) 737 5600
    Faculty address: 
    Ülikooli 18, 51014, Tartu
  • Student Council
    Faculty phone: 
    (+372) 737 5400
    Faculty address: 
    Ülikooli 18b, 51014, Tartu
Other Units
  • University of Tartu Academic Sports Club
    Faculty phone: 
    +372 737 5371
    Faculty address: 
    Ujula 4, 51008 Tartu
  • Tartu Student Village
    Faculty phone: 
    +372 740 9959
    Faculty address: 
    Narva mnt 25, 51013 Tartu
  • Tartu Students’ Club
    Faculty phone: 
    +372 730 2400
    Faculty address: 
    Kalevi 24, 51010 Tartu
  • University of Tartu Press
    Faculty phone: 
    +372 737 5945
    Faculty address: 
    W. Struve 1, 50091 Tartu
  • Tartu University Hospital
    Faculty address: 
    L. Puusepa 1a, 50406 Tartu
  • University of Tartu Foundation
    Faculty phone: 
    +372 737 5852
    Faculty address: 
    Ülikooli 18, 50090 Tartu
  • View all other units

Young scientist from the University of Tartu catching Skype scammers

A group of Microsoft researchers has used supervised machine learning to try and improve detection of fraudulent user accounts.

With Skype as their test platform, the group says it was able to achieve 68 per cent successful detection of fake accounts within four months of activity, while keeping false positives down to 5 per cent. At the same time, it claimed, it achieved a reduction in “the number of undetected fraudulent users active for over 10 months by a factor of 2.3.”

The aim, the researchers say, was to identify fraudsters “that have eluded the first line of detection systems and have been active for months”, drawing on static profile information such as age, active profile information such as the time series of a user's calls, social behaviour (adding or deleting friend contacts), and social features (such as PageRank).

The researchers note that one of their statistical techniques, the application of hidden Markov models (HMMs) to this context is new (although, interestingly, one of the authors of the paper, Moises Goldszmidt, has previously used HMMs to help predict disk failure in data centres).

The research was based on a pool of 100,000 each of legitimate and fraudulent users (as nominated by Skype), which yielded a test pool of 34,000 accounts, based on accounts which existed for 4 months without being blocked.

To protect information about users whose account information was provided by Skype for the study, the paper states that:

  • All Skype IDs were anonymized using a one-way cryptographic salted hash function
  • The only usage data applied to the study was the number of days each month that a user accessed particular features, such as chat, Skype calls, video calls, and Skype In / Skype Out.
  • Data was kept on a dedicated machine with restricted access, and the researchers planned to delete the data when their research was complete.

Although this work concentrated on Skype, “we chose not to rely on Skype's informal intent in those definitions, nor on Skype's software … in order to develop robust, self-contained methods.”

In other words, if the work proved valuable deployed to Skype, the researchers hope the techniques could be applied to other platforms as well.

Lead author Anna Leontjeva, who was an intern at Microsoft Research when she conducted the research, is an Estonian student from the University of Tartu. The paper was prepared for last November's AISec’13 in Berlin, and is available here.

Source: Richard Chirgwin, The Register.

Virge Tamme
Press Officer of the UT
Phone: +372 737 5683
Mobile: +372 5815 5392
E-mail: virge.tamme [ät] ut.ee
www.ut.ee