Although cybersecurity has become an unavoidable risk for firms, there is limited research on how firms can prevent and respond to cybersecurity risks. Based on the reputation insurance mechanism of ESG, this paper takes China’s A-share listed companies from 2010 to 2022 as the research object and empirically examines the impact and mechanism of cybersecurity risks on corporate ESG investments. The study finds that firms with higher cybersecurity risks are more likely to increase ESG investments. Lower marketization levels and higher media attention will strengthen the promoting effect of cybersecurity risks on ESG investments. Mechanism testing indicates that firms with higher cybersecurity risks can “insure” against their potential reputational risks by increasing ESG investments. Firms with greater exposure to reputational risks are more likely to increase ESG investments when faced with cybersecurity risks. Heterogeneity analysis also reveals that the positive impact of cybersecurity risks on ESG investment is more pronounced in samples with lower supply chain concentration, less managerial myopia, and a higher presence of executives with an information technology background. This paper helps understand the internal logic of firms managing cybersecurity risks through ESG investments and provides empirical evidence to encourage and guide firms to adhere to a development strategy of “technology for good”.