Zscaler Inc. ZS, -0.68% shares fell in the extended session Tuesday after the cloud security company’s earnings outlook came in below Wall Street estimates. Zscaler shares dropped 17% after hours, following a 0.7% rise in the regular session to close at $61.60. Zscaler expects adjusted earnings of break-even to a penny a share on revenue of $89 million to $90 million for the fiscal first quarter, and 12 cents to 15 cents a share on revenue of $395 million to $405 million for the year. Analysts surveyed by FactSet expect first-quarter earnings of 2 cents a share on revenue of $87.6 million, and full-year earnings of 19 cents a share on revenue of $398.4 million. The company reported a fiscal fourth-quarter loss of $5.3 million, or 4 cents a share, compared with a loss of $7 million, or 6 cents a share, in the year-ago period. Adjusted earnings were 7 cents a share. Revenue rose to $86.1 million from $56.2 million in the year-ago quarter. Analysts surveyed by FactSet had forecast earnings of a penny a share on revenue of $82.8 million.