[25][26] Some versions of MacKeeper opened a critical security hole in customers' Macs; Kromtech later issued a fix.

[27] AV-Comparatives found that MacKeeper warned of "serious" issues on a brand-new clean copy of macOS, which could only be fixed by purchasing the program.

[28] French news outlet Le Figaro called MacKeeper a scam, and criticized its reliance on "fear".

[31][7] Zeobit was accused of employing aggressive pop-under ads, planting sockpuppet reviews, and setting up websites to discredit its competitors.

[7] MacKeeper's usefulness was disputed by tech media; anti-malware, secure erase, backup, encryption, and anti-theft were either built-into macOS or available for free.

[7][34] Top Ten Reviews noted that other Mac anti-malware apps had better detection rates, resulting in a score of 7.5 out of 10.

[38] The lawsuit alleged that "neither the free trial nor the full registered versions of MacKeeper performed any credible diagnostic testing" and reported that a consumer's Mac was in need of repair and was at-risk due to harmful error.

[38] In May 2014 a lawsuit was filed against Zeobit in Pennsylvania, alleging that MacKeeper fakes security problems to deceive victims into paying for unneeded fixes.

[43] In 2014, Kromtech sued David A. Cox, who had made a video criticizing MacKeeper; the judge dismissed the case.