Despite various security features offered by distributed ledger technology (DLT), distributed ledgers are vulnerable to a variety of malicious attacks (e.g., selfish-mining and block withholding). While such vulnerabilities have been thoroughly investigated in extant research, understanding and development of appropriate countermeasures is still in its infancy. As a steppingstone for the future development of effective countermeasures, in this paper, we investigate known attacks on distributed ledgers to consolidate the underlying attack vectors and identify the focal DLT characteristics (e.g., propagation delay or confirmation latency) that are exploited in these attack vectors. Based on these insights, we accumulate potential countermeasures proposed in extant security research. The results of our work, thereby, provide a better understanding of the vulnerabilities of distributed ledgers. This understanding supports the simulation and analysis of the system behavior of distributed ledgers and the development of new countermeasures that focus on individual DLT characteristics to impede current and future attack vectors.