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MalwareUsed by 4 actorsExploits 4 CVEs

Derusbi

Also known asPHOTO

Derusbi is a stealthy remote access trojan/backdoor malware family associated with advanced persistent threat activity, particularly Chinese nexus actors including APT40, Deep Panda, and broader reporting on APT41/Wicked Panda tool usage. It is described as being used against high-value systems for espionage, data theft, and system compromise. Reported capabilities include enumerating Windows Registry keys and values, gathering the victim username, performing screen captures and audio capture, deleting files, and timestomping for defense evasion. Derusbi also uses process injection and encrypted or obfuscated communications to evade detection, and reporting notes persistence, service creation, DLL side-loading, driver loading, and lateral movement via removable drives as associated behaviors. Variants have used Registry persistence to proxy execution through regsvr32.exe, and Deep Panda reportedly used regsvr32.exe to execute a server variant of Derusbi.

Network behavior described in the content includes binding to a raw socket on a random source port between 31800 and 31900 for command and control, as well as use of unencrypted HTTP over port 443 in some cases. C2 traffic has been observed obfuscated with variable 4-byte XOR keys.

The content also describes a more advanced Derusbi-linked architecture involving a Windows x64 kernel driver/rootkit component and Linux components. The Windows driver was observed as wd.sys and udfs.sys, signed with stolen legitimate certificates, and linked to Derusbi by multiple evidences. It disables the kernel debugger, hides network connections and files, injects an encrypted userland DLL directly into memory (typically into SYSTEM svchost.exe), and communicates with userland over a named pipe of the form \.\pipe\usbpcex%d. The injected DLL stores the machine IP address in HKLM\SYSTEM\CurrentControlSet\Control\WMI\lpstatus, stores reached C2 information XORed with 0x51 in HKLM\SYSTEM\CurrentControlSet\Control\WMI\Level10, stores DNS server information in Level01, and proxy settings in Level02 through Level05. Configuration may be retrieved from a URL and parsed between the tags "$$$--Hello" and "Wrod--$$$". The driver hides connections associated with ports 1025-1777, performs kernel-level network communications using XOR encryption, optional LZO compression, and CRC32 checksums, and supports modular userland functionality including command execution, proxying, GUI/remote desktop, file operations, VPN, and uninstall/disconnect functions. The content also notes Derusbi-related Linux behavior, including loading a Linux kernel module and then deleting it from disk while overwriting the file with null bytes.

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EXPLOITED CVES

Vulnerabilities exploited

4 CVEs Mallory has correlated with this family across public research and vendor advisories. Each row links to the full Mallory page for that vulnerability.

4 CVES
CVE-2017-8759.NET Framework WSDL Parsing Remote Code Execution

PHOTO, BADFLICK, and CHINA CHOPPER are among the most frequently observed backdoors used by APT40.

via fireeyefireeye.com
CVE-2017-0199Microsoft Office/WordPad Remote Code Execution Vulnerability

PHOTO, BADFLICK, and CHINA CHOPPER are among the most frequently observed backdoors used by APT40.

via fireeyefireeye.com
CVE-2017-11882Microsoft Office Equation Editor Remote Code Execution

PHOTO, BADFLICK, and CHINA CHOPPER are among the most frequently observed backdoors used by APT40.

via fireeyefireeye.com
CVE-2012-0158MSCOMCTL.OCX ListView/TreeView ActiveX Remote Code Execution

PHOTO, BADFLICK, and CHINA CHOPPER are among the most frequently observed backdoors used by APT40.

via fireeyefireeye.com
THREAT ACTORS

Groups observed using it

4 distinct threat actors attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.

View more details
APT41

The group uses a variety of TTPs including but not limited to LoTL tactics, phishing, ransomware, cryptocurrency mining, supply chain attacks, China Chopper, Gh0st RaT, PlugX, HighNoon, Derusbi, BioPass RAT, RedXOR, and ShadowPad.

via polyswarmblog.polyswarm.io
Axiom

The group uses a variety of TTPs including but not limited to LoTL tactics, phishing, ransomware, cryptocurrency mining, supply chain attacks, China Chopper, Gh0st RaT, PlugX, HighNoon, Derusbi, BioPass RAT, RedXOR, and ShadowPad.

via polyswarmblog.polyswarm.io
Leviathan

Tools Nanhaishu, Orz, SeDll, Cobalt Strike, GreenCrash, AIRBREAK, BlackCoffee, China Chopper, FUSIONBLAZE, HOMEFRY, MURKYTOP, Metasploit / Meterpreter, ScanBox, Derusbi Trojan, Derusbi, Metasploit

via secureworks threat profilessecureworks.com
APT19

Derusbi variants have been seen that use Registry persistence to proxy execution through regsvr32.exe.

via mitre attack websiteattack.mitre.org
MITRE ATT&CK

Techniques & procedures

28 distinct techniques documented for this family, organized by ATT&CK tactic.

Initial Access

2 techniques
T1091Replication Through Removable MediaEvidence1

Utilize behavioral analytics and endpoint detection tools to identify indicators such as pesistence, service creation, lateral movement via removable drive, driver loading and dll side loading.

T1190Exploit Public-Facing ApplicationEvidence1

"APT40 has been observed leveraging a variety of techniques for initial compromise, including web server exploitation..."

Execution

1 technique
T1059.004Unix ShellEvidence1
TacticExecution

Persistence

4 techniques
T1505.003Web ShellEvidence1

"APT40 relies heavily on web shells for an initial foothold... provide continued access... re-infect... and facilitate lateral movement."

T1543.003Windows ServiceEvidence1

Utilize behavioral analytics and endpoint detection tools to identify indicators such as pesistence, service creation, lateral movement via removable drive, driver loading and dll side loading.

T1547.001Registry Run Keys / Startup FolderEvidence1

Hi-Zor executes using regsvr32.exe called from the Registry Run Keys / Startup Folder persistence mechanism. Inception has ensured persistence at system boot by setting the value regsvr32 %path%\ctfmonrn.dll /s .

T1547.006Kernel Modules and ExtensionsEvidence1

Utilize behavioral analytics and endpoint detection tools to identify indicators such as pesistence, service creation, lateral movement via removable drive, driver loading and dll side loading.

T1055Process InjectionEvidence1

Known for its adaptability, it employs techniques like process injection and encrypted communications to evade detection.

T1055.001Dynamic-link Library InjectionEvidence1
T1543.003Windows ServiceEvidence1

Utilize behavioral analytics and endpoint detection tools to identify indicators such as pesistence, service creation, lateral movement via removable drive, driver loading and dll side loading.

T1547.001Registry Run Keys / Startup FolderEvidence1

Hi-Zor executes using regsvr32.exe called from the Registry Run Keys / Startup Folder persistence mechanism. Inception has ensured persistence at system boot by setting the value regsvr32 %path%\ctfmonrn.dll /s .

T1547.006Kernel Modules and ExtensionsEvidence1

Utilize behavioral analytics and endpoint detection tools to identify indicators such as pesistence, service creation, lateral movement via removable drive, driver loading and dll side loading.

Stealth

7 techniques
T1036MasqueradingEvidence1
TacticStealth

Executables Or Script Creation In Temp Path ... T1036

T1055Process InjectionEvidence1

Known for its adaptability, it employs techniques like process injection and encrypted communications to evade detection.

T1055.001Dynamic-link Library InjectionEvidence1
T1070Indicator RemovalEvidence1
TacticStealth

Examples throughout the content include deleting tools, logs, malware-related files, staged archives, screenshots, temporary files, and exfiltrated data 'to cover their tracks,' 'reduce their footprint,' 'remove traces of activity,' or as part of 'post-intrusion cleanup.'

T1070.004File DeletionEvidence6
TacticStealth

The content repeatedly describes adversaries and malware deleting files, directories, droppers, scripts, logs, archives, staged data, and other artifacts from compromised systems, e.g., 'APT29 has used SDelete to remove artifacts from victim networks' and 'Lazarus Group malware has deleted files in various ways, including "suicide scripts" to delete malware binaries from the victim.' | The content includes secure deletion and overwrite behavior, e.g., 'APT29 has used SDelete to remove artifacts,' 'GreyEnergy can securely delete a file,' 'LiteDuke can securely delete files by first writing random data to the file,' and 'PowerDuke has a command to write random data across a file and delete it.'

T1070.006TimestompEvidence2
TacticStealth

APT28 has performed timestomping on victim files. APT29 has used timestomping to alter the Standard Information timestamps on their web shells to match other files in the same directory. APT32 has used scheduled task raw XML with a backdated timestamp... APT38 has modified data timestamps to mimic files that are in the same folder on a compromised host.

T1218.010Regsvr32Evidence2
TacticStealth

AppleSeed can call regsvr32.exe for execution. APT19 used Regsvr32 to bypass application control techniques. APT32 created a Scheduled Task/Job that used regsvr32.exe to execute a COM scriptlet that dynamically downloaded a backdoor and injected it into memory. ... Raspberry Robin uses regsvr32.exe execution without any command line parameters for command and control requests to IP addresses associated with Tor nodes.

T1056.001KeyloggingEvidence1

Discovery

6 techniques
T1012Query RegistryEvidence4
TacticDiscovery

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."

T1033System Owner/User DiscoveryEvidence2
TacticDiscovery

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.

T1057Process DiscoveryEvidence3
TacticDiscovery

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.

T1069Permission Groups DiscoveryEvidence1
TacticDiscovery

Examples include 'TrickBot can identify the user and groups the user belongs to on a compromised host' and multiple entries checking whether the current user is an administrator or has elevated privileges.

T1082System Information DiscoveryEvidence6
TacticDiscovery

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."

T1083File and Directory DiscoveryEvidence3
TacticDiscovery

“3PARA RAT has a command to retrieve metadata for files on disk as well as a command to list the current working directory… admin@338 actors used… dir c:\ >> %temp%\download … APT28 has used Forfiles to locate PDF, Excel, and Word documents…”

Lateral Movement

1 technique
T1091Replication Through Removable MediaEvidence1

Utilize behavioral analytics and endpoint detection tools to identify indicators such as pesistence, service creation, lateral movement via removable drive, driver loading and dll side loading.

Collection

3 techniques
T1056.001KeyloggingEvidence1
T1113Screen CaptureEvidence2

"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"

T1123Audio CaptureEvidence1
T1071.001Web ProtocolsEvidence1

"Common TCP ports 80 and 443 are used to blend in with routine network traffic."

T1095Non-Application Layer ProtocolEvidence1
T1571Non-Standard PortEvidence1
T1573Encrypted ChannelEvidence1

Known for its adaptability, it employs techniques like process injection and encrypted communications to evade detection.

T1573.001Symmetric CryptographyEvidence2

"3PARA RAT command and control commands are encrypted within the HTTP C2 channel using the DES algorithm in CBC mode..."; "APT33 has used AES for encryption of command and control traffic."; "Carbanak encrypts the message body of HTTP traffic with RC2 (in CBC mode)."; "Duqu ... data stream can be encrypted with AES-CBC."; "PoisonIvy uses the Camellia cipher to encrypt communications."

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets match these IOCs, which detections are missing, which campaigns to expect next, and what to do in the next 30 minutes.
IOC matching

Match every observed IP, domain, and hash against your live telemetry.

Threat actor attribution4

Named campaigns wielding this family, with evidence pinned to each claim.

Exploited vulnerabilities4

CVEs this family uses for access and lateral movement.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

MITRE ATT&CK mapping28

Every documented technique, ranked by evidence weight.

Researcher chatter

Reddit, Mastodon, and CTI community discussion around this family.