Russian hackers, who have attacked the IT management software SolarWinds in order to compromise a number of U.S. authorities and companies, are back.

Microsoft announced that the “Nobelium” spy group has built up an ongoing phishing campaign since January of this year, and this week expanded it by targeting some 3,000 people in more than 150 organizations in 24 countries.

Nobelium broke legitimate accounts of the bulk email service Constant Contact, including the service of the U.S. Agency for International Development.

Once there, the hackers were able to send spear-phishing emails that really came from the organization’s email accounts, which they were able to crack.

The emails contained legitimate links that were redirected to malicious Nobelium infrastructure and installed malicious software to control target devices.

Despite the big goals and the breach of the USAID network, the actual impact may be less severe, as automated spam systems have been able to block many of the phishing messages.

The tactics of this latest phishing campaign also reflect Nobelium’s practice of accessing one system or account and then using it to access others and skip numerous targets.

NGOs and DC think tanks have been soft targets of high value for decades, and these phishing campaigns have implications that could be felt for the long term.

It is also worth remembering that the effects of the SolarWinds attack continue months after the incident.

It is very likely that Nobelium is still present in some of the systems it compromised during this attack.

For more information, read the original story in Arstechnica.