Verb-object:
扫 ('sweep / scan') +
毒 ('poison / drugs / virus'). Same productive
扫 + noun pattern:
扫黄 (crack down on pornography),
扫黑 (crack down on organized crime),
扫雷 (clear mines). The IT 'virus scan' sense is also extremely common, especially in older Windows-era vocabulary like
扫毒软件 (antivirus software).