Lectures for 2008 - KTH

KURSKOMPENDIUM NÄTVERKSSÄKERHETSKURS
___________________________________________________________________________
2.6.2 För hög grad av integration ...............................................................................41
2.6.3 Alltför snabb adaption av nya tekniker ..............................................................42
2.6.4 Alltför komplexa lösningar................................................................................42
2.6.5 Ej uppsäkrade system........................................................................................42
2.6.6 Lättillgängliga attackverktyg.............................................................................43
2.6.7 Formgivnings- och implementationsfel .............................................................43
2.6.8 Skräppost, spam................................................................................................43
2.6.9 Nätfiske och nigeriabrev ...................................................................................44
2.7 Organisatoriska hot och risker..................................................................................46
2.7.1 Oklara ansvarsförhållanden ...............................................................................46
2.7.2 Personrisker ......................................................................................................46
2.7.3 Organisationsförändringar.................................................................................46
2.8 Administrativa hot och risker...................................................................................47
2.8.1 Okunskap om system och infrastruktur..............................................................47
2.8.2 Ojämna skyddsnivåer och felfokuserade lösningar ............................................47
2.8.3 Avtal, dokumentation, rutiner och policies saknas .............................................47
2.8.4 Bristande underhåll ...........................................................................................48
2.8.5 Bristande uppföljning........................................................................................48
2.9 Kriminella hot och risker .........................................................................................48
2.10 Sociala attacker......................................................................................................49
3 Skadlig kod ....................................................................................................................50
3.1 Exempelfall .............................................................................................................58
3.1.1 AIDS-disketten .................................................................................................58
3.1.2 Concept.............................................................................................................58
3.1.3 Code Red ..........................................................................................................59
3.1.4 Morrismasken ...................................................................................................59
3.2 Virusskydd ..............................................................................................................60
4 Nätverksarkitektur ..........................................................................................................62
4.1 Nätverkstopologi .....................................................................................................62
4.1.1 Säkerhetszoner..................................................................................................62
4.1.2 Virtuella nätverk ...............................................................................................62
4.2 Brandväggar ............................................................................................................63
4.2.1 Brandväggsprinciper .........................................................................................64
4.2.2 Paketfiltrerande brandväggar.............................................................................65
4.2.3 Applikationsbrandvägg .....................................................................................65
4.2.4 Interna brandväggar ..........................................................................................66
4.2.5 Brandväggar och yttre anslutningar ...................................................................66
4.2.6 Personliga brandväggar.....................................................................................67
4.2.7 Vad är en brandvägg inte?.................................................................................68
4.2.8 Brandväggens framtid .......................................................................................68
4.3 Adress- och portöversättning....................................................................................69
4.4 Logisk åtkomstkontroll ............................................................................................71
4.5 Honungsfällor..........................................................................................................72
4.6 Intrångsdetektering ..................................................................................................72
5 Kryptering......................................................................................................................74
5.1 Äldre kryptosystem..................................................................................................75
5.1.1 Substitutionskrypto ...........................................................................................75
5.1.2 Transpositionskrypto.........................................................................................75
5.2 Modernare kryptosystem..........................................................................................75
5.2.1 Enigma och G-skrivaren....................................................................................76
Copyright (c) 2003-2008 Robert Malmgren AB. All rights reserved Sid 3 (139)