These are heavy weapons that can give you the best idea about malware functionality, but may also take the longest time to master and work with. If you are unfamiliar with assembly, it is recommended to go through Chapter 1, A Crash Course in CISC/RISC and Programming Basics for x86/x64, first in order to get an idea of how it works. The list of known players is actually quite big, so let's split it into two rough categories—actual tools and engines (libraries).
United States
Great Britain
India
Germany
France
Canada
Russia
Spain
Brazil
Australia
Singapore
Hungary
Ukraine
Luxembourg
Estonia
Lithuania
South Korea
Turkey
Switzerland
Colombia
Taiwan
Chile
Norway
Ecuador
Indonesia
New Zealand
Cyprus
Denmark
Finland
Poland
Malta
Czechia
Austria
Sweden
Italy
Egypt
Belgium
Portugal
Slovenia
Ireland
Romania
Greece
Argentina
Netherlands
Bulgaria
Latvia
South Africa
Malaysia
Japan
Slovakia
Philippines
Mexico
Thailand