Zebrocy
Zebrocy is a malware family associated with APT28 (Fancy Bear/Sofacy/Sednit), with attribution assessed in the provided content at medium confidence. From late 2015 onward it was introduced as a parallel first-stage downloader/backdoor family and was used against embassies and ministries of foreign affairs across Eastern Europe and Central Asia. A defining characteristic noted in the content is that the same downloader/backdoor role was reimplemented across multiple programming languages while maintaining similar operational use and victimology.
The malware is described as collecting host information, including via WMI queries in some variants, Registry discovery through reg query, and enumeration of connected storage devices. It can automatically scan systems and collect files with document extensions, and some variants can capture screenshots in JPEG and BMP format. The content also states Zebrocy can upload dumper tools to extract credentials from web browsers and store them in database files.
For persistence, Zebrocy includes a command to create a scheduled task. For collection staging, it stores collected information in a single file before exfiltration. Exfiltration is performed to a designated C2 server using HTTP POST requests, and the malware has used URL/percent encoding on exfiltrated data. The content also states Zebrocy uses SSL and AES ECB for encrypting C2 communications, and that a variant used an RC4-like method together with AES and hexadecimal encoding before exfiltration.
The provided material also references continued evolution of the family, including Zebrocy v3.0 to v3.1, and notes that APT28 traditionally used Zebrocy alongside newer custom collectors/downloaders and .NET modules.
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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.
From late 2015 onwards, APT28 introduced a parallel first-stage family named Zebrocy. Its defining feature is that the same downloader and backdoor was rewritten across many languages, while keeping the same operational role and the same victims: embassies and ministries of foreign affairs across Eastern Europe and Central Asia.
Techniques & procedures
29 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial Access
1 technique
Initial Access
Execution
3 techniques
Execution
The content repeatedly describes threat actors and malware using WMI/WMIC/wmiexec for remote execution, lateral movement, discovery, persistence, and administrative actions; e.g., 'APT41 used WMI in several ways, including for execution of commands via WMIEXEC as well as for persistence via PowerSploit' and 'Scattered Spider used Windows Management Instrumentation (WMI) to move laterally via Impacket.'
During the 2022 Ukraine Electric Power Attack, Sandworm Team leveraged Scheduled Tasks through a Group Policy Object (GPO) to execute CaddyWiper at a predetermined time.
During the 2016 Ukraine Electric Power Attack, Sandworm Team used the xp_cmdshell command in MS-SQL. During the 2025 Poland Wiper Attacks, the adversaries leveraged PsExec to run cmd.exe commands on multiple victim machines. Numerous malware families and groups are described as using cmd.exe, cmd /c, Windows command shell, or command-line interfaces to execute commands, payloads, reconnaissance, persistence, cleanup, and ransomware actions.
Persistence
3 techniques
Persistence
During the 2022 Ukraine Electric Power Attack, Sandworm Team leveraged Scheduled Tasks through a Group Policy Object (GPO) to execute CaddyWiper at a predetermined time.
Across the content, malware repeatedly 'adds Registry Run keys', 'creates Registry entries', 'modifies the Windows Registry', or 'overwrites registry keys' to maintain persistence.
The content repeatedly describes malware and threat actors establishing persistence by adding values under HKCU/HKLM\Software\Microsoft\Windows\CurrentVersion\Run or RunOnce, and by placing executables, scripts, or .lnk files in the Startup folder.
Privilege Escalation
2 techniques
Privilege Escalation
During the 2022 Ukraine Electric Power Attack, Sandworm Team leveraged Scheduled Tasks through a Group Policy Object (GPO) to execute CaddyWiper at a predetermined time.
The content repeatedly describes malware and threat actors establishing persistence by adding values under HKCU/HKLM\Software\Microsoft\Windows\CurrentVersion\Run or RunOnce, and by placing executables, scripts, or .lnk files in the Startup folder.
Stealth
4 techniques
Stealth
"ADVSTORESHELL encrypts with the 3DES algorithm and a hardcoded key prior to exfiltration."; "Agent Tesla can encrypt data with 3DES..."; "APT32's backdoor has used...RC4 encryption before exfiltration."; "Epic encrypts collected data using a public key framework..."; "Some variants encrypt...with AES and encode it with base64..."; "Prikormka...encrypts it with Blowfish."; "VERMIN encrypts the collected files using 3-DES."; "Zebrocy...RC4...as well as AES...and hexadecimal for encoding"
"Sandworm Team used UPX to pack a copy of Mimikatz"; "APT38 has used several code packing methods such as Themida, Enigma, VMProtect, and Obsidium"; "Lazarus Group packed malicious .db files with Themida to evade detection."
The content repeatedly describes threat actors and malware deleting files, tools, scripts, logs, droppers, staged data, and artifacts from compromised systems to cover tracks, remove evidence, or self-delete.
The content repeatedly describes malware and threat actors decoding, decrypting, or deobfuscating payloads, strings, configuration data, commands, and C2 traffic prior to execution or use, e.g., 'APT28 macro uses the command certutil -decode to decode contents of a .txt file storing the base64 encoded payload' and 'Action RAT can use Base64 to decode actor-controlled C2 server communications.'
Defense Impairment
1 technique
Defense Impairment
Credential Access
2 techniques
Credential Access
APT3 has used tools to dump passwords from browsers... Kimsuky has also used Nirsoft's WebBrowserPassView tool to dump the passwords obtained from victims... Mimikatz performs credential dumping to obtain account and password information useful in gaining access to additional systems and enterprise network resources.
Discovery
8 techniques
Discovery
The content repeatedly describes malware and threat actors querying, enumerating, searching, reading, or checking Windows Registry keys and values, e.g., "ADVSTORESHELL can enumerate registry keys," "APT41 queried registry values to determine items such as configured RDP ports and network configurations," and "Reg may be used to gather details from the Windows Registry of a local or remote system at the command-line interface."
The content repeatedly describes actors and malware using commands and APIs such as ipconfig /all, ifconfig, arp -a, route print, netsh interface show, GetAdaptersInfo, and GetIpNetTable to gather IP addresses, MAC addresses, DNS, DHCP, gateways, routing tables, ARP cache, proxy settings, and network adapter/interface details.
The content repeatedly describes malware and threat actors collecting usernames, identifying logged-in users, running whoami/query user/quser, checking admin status, and enumerating user sessions.
The content repeatedly describes malware and threat actors obtaining lists of running processes, using utilities such as tasklist, ps, WMI, Get-Process, CreateToolhelp32Snapshot, EnumProcesses, and similar APIs/commands to enumerate active processes on victim systems.
The content repeatedly describes malware and threat actors collecting host details such as OS version, hostname, architecture, CPU, memory, BIOS, domain, language, and other configuration data; e.g., "APT41 uses multiple built-in commands such as systeminfo and net config Workstation to enumerate victim system basic configuration information."
"...has a command to retrieve metadata for files on disk as well as a command to list the current working directory." / "...can list files and directories." / "...used the following commands... to obtain information about files and directories: dir c:\ >> %temp%\download ..."
The content repeatedly describes malware and threat actors identifying, monitoring, or enumerating connected peripheral devices such as USB mass storage, Bluetooth devices, printers, smart card readers, cameras, Apple devices, VGA/display devices, and removable drives.
Multiple malware and threat groups are described as collecting/deriving local system time, date, timestamp, tick count, or time zone (e.g., "used time /t and net time \ip/hostname for system time discovery"; "collects the timestamp from the victim’s machine"; "can collect the time zone information from the system").
Collection
4 techniques
Collection
Confucius has used a file stealer to steal documents and images with the following extensions: txt, pdf, png, jpg, doc, xls, xlm, odp, ods, odt, rtf, ppt, xlsx, xlsm, docx, pptx, and jpeg.
The content repeatedly describes adversaries and malware storing collected data, command output, credentials, archives, or files in local temporary folders, working directories, hidden directories, registry locations, recycle bins, or specific files prior to exfiltration.
"Agent Tesla can capture screenshots of the victim’s desktop"; "AppleSeed can take screenshots on a compromised host"; "APT28 has used tools to take screenshots from victims"; "Cobalt Strike's Beacon payload is capable of capturing screenshots"; "PowerSploit's Get-TimedScreenshot Exfiltration module can take screenshots at regular intervals"; "Hydraq includes a component based on the code of VNC that can stream a live feed of the desktop"
"AppleSeed has compressed collected data before exfiltration."; "APT28 used a publicly available tool to gather and compress multiple documents..."; "Aria-body has used ZIP to compress data..."; "Cadelspy...compress stolen data into a .cab file."; "Daserf hides collected data in password-protected .rar archives."; "FIN6 has compressed log files into a ZIP archive prior to staging and exfiltration."; "Lazarus Group has compressed exfiltrated data with RAR...archive specified directories in .zip format"; "XCSSET will compress entire ~/Desktop folders..."
Command and Control
4 techniques
Command and Control
The content repeatedly describes threat actors, malware, and campaigns using HTTP and/or HTTPS for command and control, including examples such as BlackEnergy communicating with C2 over HTTP POST requests and many other families using HTTP/S for C2.
C2 traffic from ADVSTORESHELL is encrypted, then encoded with Base64 encoding... APT19 HTTP malware variant used Base64 to encode communications to the C2 server... APT33 has used base64 to encode command and control traffic.
The content repeatedly describes malware and threat actors using SSL, TLS, HTTPS, RSA, AES, Blowfish, RC4, ECIES, Diffie-Hellman, OpenSSL, WolfSSL, and mutual TLS to protect command and control traffic.
Multiple malware families and intrusion sets are described as encrypting C2 traffic using SSL/TLS/HTTPS (e.g., "used HTTPS for command and control", "encrypts C2 communications with TLS", "uses SSL for encrypting C2 communications", "TLS-encrypted WebSocket Protocol (WSS) for C2"). | Examples include: "encrypt C2 messages with AES-256-CBC sent underneath TLS", "encrypts C2 traffic with AES and RSA", "uses SSL/TLS and RC4", and "BlowFish algorithm".
Recent activity
67 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A multilingual first-stage downloader and backdoor family used against embassies and ministries of foreign affairs, often treated as an APT28-associated operational cluster.
... Zebrocy ... (v3.0→v3.1) ...
Zebrocy (v3.0→v3.1)
Zebrocy is a malware family used by APT28 for espionage, featuring multiple components for initial access, persistence, and data exfiltration.
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.
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Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.