  Since the early 1960, industrial process control has been applied by electric
systems. In the mid 1970's, the term SCADA emerged, describing the automated
control and data acquisition. Since most industrial and automation networks
were physically isolated, security was not an issue. This changed, when in the
early 2000's industrial networks were opened to the public internet. The
reasons were manifold. Increased interconnectivity led to more productivity,
simplicity and ease of use. It decreased the configuration overhead and
downtimes for system adjustments. However, it also led to an abundance of new
attack vectors. In recent time, there has been a remarkable amount of attacks
on industrial companies and infrastructures. In this paper, known attacks on
industrial systems are analysed. This is done by investigating the exploits
that are available on public sources. The different types of attacks and their
points of entry are reviewed in this paper. Trends in exploitation as well as
targeted attack campaigns against industrial enterprises are introduced.
