  Underground online forums are platforms that enable trades of illicit
services and stolen goods. Carding forums, in particular, are known for being
focused on trading financial information. However, little evidence exists about
the sellers that are present on carding forums, the precise types of products
they advertise, and the prices buyers pay. Existing literature mainly focuses
on the organisation and structure of the forums. Furthermore, studies on
carding forums are usually based on literature review, expert interviews, or
data from forums that have already been shut down. This paper provides
first-of-its-kind empirical evidence on active forums where stolen financial
data is traded. We monitored 5 out of 25 discovered forums, collected posts
from the forums over a three-month period, and analysed them quantitatively and
qualitatively. We focused our analyses on products, prices, seller prolificacy,
seller specialisation, and seller reputation.
