MAYBEROBOT
MAYBEROBOT is a PowerShell backdoor in COLDRIVER’s/ColdRiver’s/Star Blizzard’s/UNC4057’s ROBOT malware suite, also tracked by Zscaler as SIMPLEFIX. Reporting states it replaced the earlier Python backdoor YESROBOT after public disclosure of COLDRIVER’s LOSTKEYS malware in May 2025, and became the actor’s preferred implant due to being more flexible and extensible and not requiring a Python installation on the victim host.
The malware has been delivered through multi-stage intrusion chains associated with fake CAPTCHA or ClickFix-style lures, where victims are tricked into executing malicious code. In other observed activity, TA446/COLDRIVER campaigns delivered MAYBEROBOT via password-protected ZIP files. GTIG reported that NOROBOT commonly acted as the downloader/stager for MAYBEROBOT, including a simplified June 2025 variant that fetched a single file to establish persistence via a Windows logon script, which then executed PowerShell to download and run a heavily obfuscated MAYBEROBOT payload. Other reporting also describes COLDRIVER updating the MAYBEROBOT/SIMPLEFIX delivery chain with self-infection via ClickFix and adding DGA and RSA-based authenticity checks for C2.
High-confidence capabilities directly described in the content include use of a hardcoded C2 server and a custom protocol supporting three operator-driven actions: downloading and executing content from a specified URL, executing commands via cmd.exe, and executing arbitrary PowerShell blocks. MAYBEROBOT sends acknowledgements to one C2 path and sends command output for cmd.exe and PowerShell execution to a separate C2 path. GTIG assessed that MAYBEROBOT has minimal built-in functionality and relies on operators to supply more complex commands.
The malware is associated with Russian state-sponsored espionage activity attributed to COLDRIVER, also known as Star Blizzard, Callisto, and UNC4057; separate reporting also refers to the actor as TA446 and assesses affiliation with Russia’s FSB. The activity is described as intelligence collection against high-value targets, including Western governments, NGOs, policy organizations, think tanks, academia, journalists, dissidents, and related sectors. Google reported observing delivery activity from June through September 2025 and published indicators of compromise and YARA rules for the broader ROBOT malware activity. Specific hashes mentioned in connection with MAYBEROBOT staging include b60100729de2f468caf686638ad513fe28ce61590d2b0d8db85af9edc5da98f9 for a heavily obfuscated PowerShell script downloaded as the next stage, and 3b49904b68aedb6031318438ad2ff7be4bf9fd865339330495b177d5c4be69d1 for a simplified NOROBOT variant involved in the chain.
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Groups observed using it
1 distinct threat actor attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
MAYBEROBOT: The actor’s current tool of choice — a more flexible and extensible PowerShell backdoor.
Techniques & procedures
15 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial Access
1 techniqueThe hacking group is known for spear-phishing campaigns aimed at harvesting credentials from targets of interest. The latest activity involves using fake "discussion invitation" emails spoofing the Atlantic Council...
Execution
4 techniquesMAYBEROBOT: The actor’s current tool of choice — a more flexible and extensible PowerShell backdoor.
"...supports three commands: ... execute commands through the command prompt"
The new infection chain, themed around CAPTCHA lures, features a family of malware we’ve named the “ROBOT” suite
These attacks lead to the deployment of a known backdoor referred to as MAYBEROBOT via password-protected ZIP files.
Persistence
2 techniques"...fetches a single file, which we observed to be a single command that sets up a logon script for persistence. The logon script was a Powershell command which downloaded and executed the next stage..."
Privilege Escalation
1 techniqueStealth
2 techniques"...complex delivery chain that splits cryptographic keys across multiple components. Decrypting the final payload depended on combining the pieces correctly..."
"...trick victims into manually launching a disguised program file..." and "...embedding malicious code into fake PDF documents and convincing targets to download a 'decryption' utility..."
Defense Impairment
1 techniqueCollection
2 techniquesThese attacks lead to the deployment of a known backdoor referred to as MAYBEROBOT via password-protected ZIP files.
The campaign showed higher-than-usual activity, previously delivering the MAYBEROBOT backdoor via password-protected ZIP files.
Command and Control
4 techniques"...uses a hardcoded C2 and a custom protocol... In all cases an acknowledgement is sent to the C2 at a different path... output is sent to a third path."
"download and execute payloads from a specified URL" and "initially retrieved a full Python 3.8 installation for Windows"
“enhanced attacker-side security measures, such as DGA and RSA-based authenticity checks for C2 communications.”
“DGA and RSA-based authenticity checks for C2 communications.”
IOCs tracked for this family
1 indicator attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.
IPs, domains, and DNS infrastructure linked to this family.
Recent activity
11 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A backdoor previously delivered by TA446 in phishing campaigns via password-protected ZIP archives.
A backdoor deployed in TA446 email attacks via password-protected ZIP archives.
Multi-stage malware delivery chain used by COLDRIVER; updated to include additional stagers and attacker-side protections such as DGA and RSA-based authenticity checks for C2.
Multi-stage malware delivery chain used by COLDRIVER, incorporating ClickFix-style self-infection and additional stagers with DGA and RSA-based authenticity checks for C2 communications.
The version that knows your environment.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.