Electronic Commerce (E-Commerce) was created to help expand the market share network through the internet without the boundaries of space and time. However, behind all the benefits obtained, E-Commerce also raises the issue of consumer concerns about the responsibility for personal data that has been recorded and collected by E-Commerce companies. The personal data is in the form of consumer identity names, passwords, debit and credit card numbers, conversations in email, as well as information related to consumer requests. In Indonesia, cyber attacks have occurred several times against 3 major E-Commerce companies in Indonesia. In 2019, users' personal data in the form of email addresses, telephone numbers, and residential addresses were sold on the deep web at Bukalapak and Tokopedia. Even though E-Commerce affected by the cyber attack already has a Computer Security Incident Response Team (CSIRT) by recruiting various security engineers, both defense and attack, this system still has a weakness, namely that the CSIRT operates in the aspect of handling and experimenting with defense, not yet on how to store data and prepare for forensics. CSIRT will do the same thing again, and so on. This is called an iterative procedure, one day the attack will come back and only be done with technical handling. Previous research has succeeded in revealing that organizations that have Knowledge Management (KM), the organization has succeeded in reducing costs up to four times from the original without using KM in the cyber security operations. The author provides a solution to create a knowledge management strategy for handling cyber incidents in CSIRT E-Commerce in Indonesia. This research resulted in 4 KM Processes and 2 KM Enablers which were then translated into concrete actions. The KM Processes are Knowledge Creation, Knowledge Storing, Knowledge