Angola's largest telecommunications company, Unitel, was hit by a cyberattack that disrupted mobile, internet and voice services across the country just hours before its shares were due to begin trading in one of the country's most closely watched stock market listings.

The state-controlled operator said it detected the attack at about 2:20 a.m. local time on Tuesday, triggering widespread disruptions across its technology infrastructure and affecting services for millions of customers nationwide.

Unitel, which serves more than 21 million subscribers in a country of about 39 million people, said engineers were working to restore services but did not disclose the nature of the cyberattack or indicate when normal operations would resume.

The incident comes at a crucial moment for both the company and Angola's capital markets. On Wednesday, Unitel is expected to begin trading on the Angola Debt and Securities Exchange (BODIVA) following a $329 million (300.3 billion kwanza) initial public offering that drew demand exceeding the shares available by more than 20%, underscoring strong investor appetite despite a challenging global investment climate.

Business Insider Africa earlier reported that the government sold a 15% stake in Unitel at the top end of its price range, with more than 17,500 investor orders accepted during the offer period. The transaction forms part of President João Lourenço's privatisation programme aimed at reducing state ownership of major companies and deepening Angola's capital markets.

While there is no indication that the cyberattack affected the IPO process or trading infrastructure, the timing places fresh attention on cybersecurity risks facing companies undergoing major market events.

Cyberattacks targeting telecommunications companies can disrupt not only consumer communications but also banking services, digital payments, enterprise networks and government communications that rely on telecom infrastructure.

For investors, such incidents have become an increasingly important measure of operational resilience, particularly as telecom operators expand digital services, mobile financial platforms and cloud infrastructure across Africa.

The attack also highlights the growing cybersecurity challenges confronting Africa's rapidly expanding digital economy. Telecommunications operators are increasingly attractive targets because they underpin internet access, mobile banking, digital commerce and public services. As more African governments privatise strategic assets and encourage digital investment, cyber resilience has become a key factor in maintaining investor confidence.

For Angola, Unitel's listing represents more than a corporate milestone. It is expected to become the first telecommunications company listed on BODIVA, broadening a stock exchange that has traditionally been dominated by financial institutions and supporting the government's wider effort to attract private capital into the economy.

The company did not attribute the attack to any specific group, and authorities have not announced an investigation or identified the perpetrators.