The COVID-19 pandemic fundamentally reshaped higher education by forcing institutions into a rapid transition to online learning. Universities have had to quickly incorporate and adjust existing technical resources to accommodate this abrupt transition. This has also involved professors and researchers who may not possess a natural, technological aptitude for online instruction. This experience has not only accelerated the adoption of technology in higher education but also highlighted the need for flexibility, accessibility, and innovation in online teaching and learning after the pandemic. This study thus aims to examine the transformative impact of COVID-19 on student attitudes and behaviors towards online learning at the University of Economics Ho Chi Minh City (UEH) in Vietnam. After collecting data from 758 students enrolled at UEH, we utilize SPSS 28 to analyze the sample distribution and Smart PLS 4.0 to analyze the Partial Least Squares Structural Equation Modelling (PLS-SEM) model. The study findings reveal that support from university management and the characteristics of lecturers significantly affect learners' attitudes towards online learning. These attitudes, in turn, affect students' online learning behaviors throughout both the duration and aftermath of the COVID-19 pandemic. Our study findings also show that increased awareness of the serious consequences of COVID-19 drives proactive engagement in online learning behaviors during the pandemic. Furthermore, this impact on behaviors persists even after the crisis is under control. The implications of this study are important for university management, highlighting the potential to transform the challenges posed by COVID19 into opportunities for sustainable development in online teaching and learning, complementing traditional classroom education in the long term.