Bazar
Bazar, commonly known as BazaLoader, is a first-stage downloader/loader first identified in 2020. It has been associated with follow-on ransomware activity, including Conti, and has been used in campaigns overlapping with the DEV-0193/Trickbot ecosystem; Microsoft describes DEV-0193 as responsible for developing, distributing, and managing payloads including Trickbot, BazaLoader, and AnchorDNS. Wizard Spider has also used spearphishing attachments to deliver documents with macros or PDFs containing malicious links that download Bazar. Related reporting notes overlap between infrastructure used to deliver BazaLoader and Trickbot payloads and infrastructure involved in August 2021 CVE-2021-40444 exploitation activity.
Observed capabilities in the provided content include TLS-encrypted C2 communications; execution of PowerShell scripts received from C2; execution of WMI queries to identify the installed antivirus engine; querying Windows\CurrentVersion\Uninstall to enumerate installed applications; creating scheduled tasks for persistence; enumerating remote systems with Net View; and code injection via VirtualAllocExNuma. Bazar also performs defense evasion and anti-analysis behaviors, including checking that the operating system keyboard and language settings are not set to Russian, manually loading ntdll from disk to identify and remove API hooks placed by security products, and attempting to overload sandbox analysis by issuing 1550 printf calls. The malware has also been observed signed with fake certificates, including certificates appearing to be from VB CORPORATE PTY. LTD.
In campaign context, Sophos reported that in some Ryuk attacks involving SystemBC, initial compromise came from phishing emails delivering Buer Loader, while related attacks in the same campaign used Bazar or Zloader. The content also notes increased botnet activity after the Emotet takedown in which Bazar was among the major C2 families detected. A cited DFIR Report article title, "CONTInuing the Bazar Ransomware Story," further indicates linkage between Bazar activity and Conti-related ransomware operations.
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Vulnerabilities exploited
1 CVE Mallory has correlated with this family across public research and vendor advisories. Each row links to the full Mallory page for that vulnerability.
Additionally, some of the infrastructure that hosted the oleObjects utilized in the August 2021 attacks abusing CVE-2021-40444 were also involved in the delivery of BazaLoader and Trickbot payloads — activity that overlaps with a group Microsoft tracks as DEV-0193. | In August, Microsoft Threat Intelligence Center (MSTIC) identified a small number of attacks (less than 10) that attempted to exploit a remote code execution vulnerability in MSHTML using specially crafted Microsoft Office documents. These attacks used the vulnerability, tracked as CVE-2021-40444, as part of an initial access campaign that distributed custom Cobalt Strike Beacon loaders.
Groups observed using it
6 distinct threat actors attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
BazaLoader is a first stage downloader first identified in 2020 that has been associated with follow-on ransomware campaigns including Conti.
DEV-0193 is responsible for developing, distributing, and managing many different payloads, including Trickbot, Bazaloader, and AnchorDNS.
DEV-0193 is responsible for developing, distributing, and managing many different payloads, including Trickbot, Bazaloader, and AnchorDNS.
"In Q4, it was responsible for a wave attacks against the healthcare sector using a loader called BazaLoader. BazaLoader... subsequently installed a ransomware strain called Ryuk."
"...other recent attacks have used another Trickbot-connected backdoor known as Bazar."
Microsoft attributes this campaign to Storm-0249... known for distributing, at minimum, BazaLoader, IcedID, Bumblebee, and Emotet malware.
Techniques & procedures
35 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial Access
2 techniquesProofpoint researchers have observed Bumblebee being distributed in email campaigns by at least three tracked threat actors.
A smaller subset of entries mention attachments or PDFs containing malicious links, such as 'Wizard Spider has used spearphishing attachments to deliver ... PDFs containing malicious links to download either Emotet, Bokbot, TrickBot, or Bazar' and 'XLoader has been delivered as a phishing attachment, including PDFs with embedded links.'
Execution
5 techniquesThe 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.
The content repeatedly describes threat actors and malware using PowerShell scripts/commands for execution, download, staging, reconnaissance, persistence, credential access, lateral movement, and defense evasion; e.g., "Sandworm Team used PowerShell scripts to run a credential harvesting tool in memory to evade defenses."
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 techniquesDuring 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, .lnk files, or .bat files in the Windows Startup folder.
Privilege Escalation
3 techniquesDuring 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 injecting shellcode, DLLs, or payloads into legitimate processes such as svchost.exe, explorer.exe, iexplore.exe, cmd.exe, lsass.exe, and browser processes.
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, .lnk files, or .bat files in the Windows Startup folder.
Stealth
11 techniquesThe content repeatedly describes payloads, strings, configuration files, scripts, URLs, and binaries being obfuscated or encoded using Base64, XOR, RC4, AES, RSA, hex encoding, custom algorithms, and other methods across many malware families and threat actors.
Examples throughout the content include 'encrypted payloads decrypted and executed in memory,' 'encrypts its configuration file,' 'AES-encrypted resource,' 'RC4 encrypted embedded scripts,' and 'payload includes an encrypted main component.'
During the 2016 Ukraine Electric Power Attack, DLLs and EXEs with filenames associated with common electric power sector protocols were used to masquerade files.
Akira has used legitimate names and locations for files to evade defenses.
The content repeatedly describes malware and threat actors injecting shellcode, DLLs, or payloads into legitimate processes such as svchost.exe, explorer.exe, iexplore.exe, cmd.exe, lsass.exe, and browser processes.
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.'
In this post I’ll work through analyzing an AppX package from Magnitude Exploit Kit that drops Magniber... AppX packages have gotten some mileage as droppers lately.
"Bazar can attempt to overload sandbox analysis by sending 1550 calls to printf."
The content includes multiple anti-analysis and environment checks, such as "OopsIE checks for information on the CPU fan, temperature, mouse, hard disk, and motherboard as part of its anti-VM checks" and "Raspberry Robin performs several system checks as part of anti-analysis mechanisms."
Defense Impairment
2 techniquesAcross 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 threat actors and malware using valid, stolen, forged, self-signed, or abused code-signing certificates to sign malware and appear legitimate, including examples such as AppleJeus using a valid digital signature from Sectigo, APT41 leveraging code-signing certificates, FIN7 signing Carbanak payloads, and SUNBURST being digitally signed by SolarWinds.
Discovery
11 techniquesThe 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.
During the 2015 Ukraine Electric Power Attack, Sandworm Team remotely discovered systems over LAN connections. OT systems were visible from the IT network as well, giving adversaries the ability to discover operational assets.
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 ..."
"Bazar can attempt to overload sandbox analysis by sending 1550 calls to printf."
The content includes multiple anti-analysis and environment checks, such as "OopsIE checks for information on the CPU fan, temperature, mouse, hard disk, and motherboard as part of its anti-VM checks" and "Raspberry Robin performs several system checks as part of anti-analysis mechanisms."
Examples include 'Action RAT can use WMI to gather AV products installed on an infected host,' 'FlawedAmmyy leverages WMI to enumerate anti-virus on the victim,' and 'TA2541 has used WMI to query targeted systems for security products.'
Examples include "Bazar can also check if the Russian language is installed on the infected machine and terminate if it is found," "DropBook has checked for the presence of Arabic language," and "Maze has checked the language of the infected system using the GetUSerDefaultUILanguage function."
Collection
1 techniqueThe content repeatedly describes threat actors and malware collecting, stealing, identifying, copying, or staging files, documents, credentials, logs, databases, and other information from compromised hosts or local systems.
Command and Control
4 techniquesRecorded Future tracks the creation and modification of new malicious infrastructure for a multitude of post-exploitation toolkits, custom malware, and open-source remote access trojans (RATs). We observed over 17,000 unique command-and-control (C2) servers during 2022...
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.
...results in (1) the download of a CAB file containing a DLL bearing an INF file extension... The DLL retrieves remotely hosted shellcode (in this instance, a custom Cobalt Strike Beacon loader)...
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.
Other
1 techniqueRecent activity
90 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Bazar is referenced as a loader used in the same Ryuk campaign to gain initial access before follow-on tooling such as SystemBC and ransomware deployment.
Referenced as malware historically distributed by Storm-0249 (no additional functional detail provided in the content).
Loader/backdoor malware capable of code injection using VirtualAllocExNuma.
Named botnet/loader family referenced as part of elevated botnet activity following the Emotet takedown.
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.