MyConc.bad(address) (tests/unchecked_lowlevel-0.5.1.sol#2-4) ignores return value by dst.call.value(msg.value)() (tests/unchecked_lowlevel-0.5.1.sol#3) Reference: https://github.com/crytic/slither/wiki/Detector-Documentation#unchecked-low-level-calls tests/unchecked_lowlevel-0.5.1.sol analyzed (1 contracts with 1 detectors), 1 result(s) found Use https://crytic.io/ to get access to additional detectors and Github integration