StrelaStealer malware steals email login data from popular email clients and sends it to the attacker’s server. The attacker can then use this information to launch more attacks. Since its first appearance in 2022, the threat actor has carried out many email campaigns and shows no sign of stopping.
Unit42 researchers have found a wave of big StrelaStealer campaigns affecting more than 100 organizations in the EU and U.S. These campaigns involve spam emails with attachments that activate the StrelaStealer’s DLL payload.
By infosecbulletin
/ Saturday , August 1 2026
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) warns of a big rise in attacks on internet-connected programmable logic controllers...
Read More
By infosecbulletin
/ Friday , July 31 2026
A new open-source project named CyberStrike aims to be the first AI tool made for offensive security. It can turn...
Read More
By infosecbulletin
/ Friday , July 31 2026
Many countries are now showing interest to invest in the data center industry in Banglades especially in AI data centers....
Read More
By infosecbulletin
/ Thursday , July 30 2026
NVIDIA has revealed a big flaw with its BlueField DPUs and ConnectX networking systems. This issue could let attackers run...
Read More
By infosecbulletin
/ Wednesday , July 29 2026
India's leading state-owned lender Bank of Baroda acknowledged Monday a security incident after reports that approximately 1 terabyte of customer...
Read More
By infosecbulletin
/ Tuesday , July 28 2026
CISA has put the Fortinet FortiOS vulnerability CVE-2025-68686 in its list of known exploited flaws after ongoing attacks. The flaw...
Read More
By infosecbulletin
/ Tuesday , July 28 2026
OpenAI's CEO Sam Altman says that AI has reached a big milestone. The technology can now make itself better, leading...
Read More
By infosecbulletin
/ Tuesday , July 28 2026
ShinyHunters has publicly claimed responsibility for the Ernst & Young (EY) data breach. The group posted a message on their...
Read More
By infosecbulletin
/ Monday , July 27 2026
Nvidia and over 30 tech firms started a group on Monday to create open-source AI tools for protecting against cyber...
Read More
By infosecbulletin
/ Monday , July 27 2026
Claude's share links from Anthropic showed up in public search results. This raised new privacy worries for users who shared...
Read More
Attackers change email attachment file formats to evade detection. This prevents detection from previously generated signatures or patterns. The malware author frequently updates the DLL payload with improved obfuscation and anti-analysis techniques. This makes analysis more difficult for analysts and security products.
Last Large-Scale Campaign of 2023:
StrelaStealer has been causing multiple large-scale campaigns. The most recent campaign in November 2023 targeted organizations in the U.S. and EU. Figure 1 shows the timeline of this campaign.

Recent Large-Scale Campaign in 2024
In January 2024, the StrelaStealer threat actors started a big campaign targeting organizations in the same areas as before. The campaign peaked on Jan. 29, 2024.

The language of the StrelaStealer spam email seen during this campaign is localized and the subject line has the pattern of Factura/Rechnung/invoice####. Figure 3, below, is a sample email in German.
Figure 4 shows that while this recent campaign seems to target organizations in many industries, organizations in the high tech industry have been the largest target.

For the technical analysis click here.