Microsoft issued a public warning on December 14 that hackers linked to the governments of China, Iran, North Korea, and Turkey are working to exploit a flaw in the Java-based Log4j software that could affect hundreds of millions of computer systems, including those used by governments and major corporations. According to Microsoft, the Iranian group has deployed ransomware in the past. A senior US Cybersecurity and Infrastructure Security Agency official said that there was no evidence federal networks had been breached.

Nuclear negotiators in Vienna ended their first week of talks without a deal and returned to their capitals for consultations on December 3rd. European Union chief diplomat Enrique Mora said that there needs to be a "convergence of policy" for negotiations to proceed. Iranian negotiators repeated a demand for the United States to unfreeze $10 billion in assets. The goal of the talks is to bring Iran and the United States back into compliance with the Joint Comprehensive Plan of Action (JCPOA), the 2015 agreement limiting Iran's nuclear program in exchange for sanctions relief. From Dubai, French president Emmanuel Macron voiced skepticism about the eventual outcome of the talks and said it was important to discuss "other regional issues" beyond Iran's nuclear program. 

An international arbitration panel ruled in late November that Bahrain's government acted improperly when it closed Future Bank in 2015. The bank was a joint venture between Bank Melli and Bank Saderat, two Iranian banks that have been sanctioned by the United States. Bahraini officials argued that Future Bank had to be closed to protect investors from alleged corruption and sanctions violations. However, The Hague-based panel found that Bahrain's actions were not consistent with Bahrain's own banking laws and may have had political motivations, as Iran is a regional rival. It ordered the government of Bahrain to pay the banks more than $270 million in compensation, which Bahrain plans to appeal.

Iranian airline Mahan Air's website was temporarily rendered inaccessible by a cyberattack on November 21. A group calling itself Hoosyarane-Vatan, or Observants of Fatherland, claimed responsibility in text messages sent to Mahan Air customers citing Mahan Air's cooperation with the Islamic Revolutionary Guard Corps (IRGC). The airline has been sanctioned by the United States since 2011 for providing support to the IRGC. Iran has experienced other large-scale cyberattacks this year, including one that disabled gas stations in October and another that disrupted the country's railroad system in July.