Complex sentence: Ivanov was able to obtain superuser (root) access to OIB machines and "control the data, e.g. credit card numbers and merchant account numbers, stored in OIB computers".
Split into simpler sentences: Ivanov was able to obtain superuser (root) access to OIB machines. By gaining root access to OIB's machines, Ivanov was effectively able to "control the data, e.g. credit card numbers and merchant account numbers, stored in OIB computers".