T1505.003: Web Shell

CURIUM is an Iranian threat group, first reported in September 2019 and active since at least July 2018, targeting IT service providers in the Middle East.[1] CURIUM has since invested in building relationships with potential targets via social media over a period of months to establish trust and confidence before sending malware. Security researchers note CURIUM has demonstrated great patience and persistence by chatting with potential targets daily and sending benign files to help lower their security consciousness.[2]

Dragonfly is a cyber espionage group that has been attributed to Russia's Federal Security Service (FSB) Center 16.[1][2] Active since at least 2010, Dragonfly has targeted defense and aviation companies, government entities, companies related to industrial control systems, and critical infrastructure sectors worldwide through supply chain, spearphishing, and drive-by compromise attacks.[3][4][5][6][7][8][9]

APT28 is a threat group that has been attributed to Russia's General Staff Main Intelligence Directorate (GRU) 85th Main Special Service Center (GTsSS) military unit 26165.[1][2] This group has been active since at least 2004.[3][4][5][6][7][8][9][10][11][12][13]

APT28 reportedly compromised the Hillary Clinton campaign, the Democratic National Committee, and the Democratic Congressional Campaign Committee in 2016 in an attempt to interfere with the U.S. presidential election.[5] In 2018, the US indicted five GRU Unit 26165 officers associated with APT28 for cyber operations (including close-access operations) conducted between 2014 and 2018 against the World Anti-Doping Agency (WADA), the US Anti-Doping Agency, a US nuclear facility, the Organization for the Prohibition of Chemical Weapons (OPCW), the Spiez Swiss Chemicals Laboratory, and other organizations.[14] Some of these were conducted with the assistance of GRU Unit 74455, which is also referred to as Sandworm Team.

OilRig is a suspected Iranian threat group that has targeted Middle Eastern and international victims since at least 2014. The group has targeted a variety of sectors, including financial, government, energy, chemical, and telecommunications. It appears the group carries out supply chain attacks, leveraging the trust relationship between organizations to attack their primary targets. The group works on behalf of the Iranian government based on infrastructure details that contain references to Iran, use of Iranian infrastructure, and targeting that aligns with nation-state interests.[1][2][3][4][5][6][7]

FIN13 is a financially motivated cyber threat group that has targeted the financial, retail, and hospitality industries in Mexico and Latin America, as early as 2016. FIN13 achieves its objectives by stealing intellectual property, financial data, mergers and acquisition information, or PII.[1][2]

BackdoorDiplomacy is a cyber espionage threat group that has been active since at least 2017. BackdoorDiplomacy has targeted Ministries of Foreign Affairs and telecommunication companies in Africa, Europe, the Middle East, and Asia.[1]

Agrius is an Iranian threat actor active since 2020 notable for a series of ransomware and wiper operations in the Middle East, with an emphasis on Israeli targets.[1][2] Public reporting has linked Agrius to Iran's Ministry of Intelligence and Security (MOIS).[3]

Deep Panda is a suspected Chinese threat group known to target many industries, including government, defense, financial, and telecommunications. [1] The intrusion into healthcare company Anthem has been attributed to Deep Panda. [2] This group is also known as Shell Crew, WebMasters, KungFu Kittens, and PinkPanther. [3] Deep Panda also appears to be known as Black Vine based on the attribution of both group names to the Anthem intrusion. [4] Some analysts track Deep Panda and APT19 as the same group, but it is unclear from open source information if the groups are the same. [5]

APT39 is one of several names for cyber espionage activity conducted by the Iranian Ministry of Intelligence and Security (MOIS) through the front company Rana Intelligence Computing since at least 2014. APT39 has primarily targeted the travel, hospitality, academic, and telecommunications industries in Iran and across Asia, Africa, Europe, and North America to track individuals and entities considered to be a threat by the MOIS.[1][2][3][4][5]

Mustang Panda is a China-based cyber espionage threat actor that has been conducting operations since at least 2012. Mustang Panda has been known to use tailored phishing lures and decoy documents to deliver malicious payloads. Mustang Panda has targeted government, diplomatic, and non-governmental organizations, including think tanks, religious institutions, and research entities, across the United States, Europe, and Asia, with notable activity in Russia, Mongolia, Myanmar, Pakistan, and Vietnam. [1][2][3][4][5][6][7][8][9][10][11][12][13]

Volatile Cedar is a Lebanese threat group that has targeted individuals, companies, and institutions worldwide. Volatile Cedar has been operating since 2012 and is motivated by political and ideological interests.[1][2]

GALLIUM is a cyberespionage group that has been active since at least 2012, primarily targeting telecommunications companies, financial institutions, and government entities in Afghanistan, Australia, Belgium, Cambodia, Malaysia, Mozambique, the Philippines, Russia, and Vietnam. This group is particularly known for launching Operation Soft Cell, a long-term campaign targeting telecommunications providers.[1] Security researchers have identified GALLIUM as a likely Chinese state-sponsored group, based in part on tools used and TTPs commonly associated with Chinese threat actors.[1][2][3]

P.A.S. Webshell is a publicly available multifunctional PHP webshell in use since at least 2016 that provides remote access and execution on target web servers.[1]

OwaAuth is a Web shell and credential stealer deployed to Microsoft Exchange servers that appears to be exclusively used by Threat Group-3390. [1]

PHPsert is a webshell used to execute PHP code that has been in use since at least 2023 against targets in Japan, Singapore, Peru, Taiwan, Iran, Republic of Korea, and the Philippines. PHPsert is not typically deployed as a standalone but integrated into web content such as text editors and content management systems.[1]

WIREFIRE is a web shell written in Python that exists as trojanized logic to the visits.py component of Ivanti Connect Secure VPN appliances. WIREFIRE was used during Cutting Edge for downloading files and command execution.[1]

SPAWNCHIMERA is a backdoor that supports command and control and can inject malicious components into native processes.[1][2][3] SPAWNCHIMERA It incorporates capabilities from multiple tools within the SPAWN malware family, including SPAWNANT, SPAWNMOLE, and SPAWNSNAIL.[4][2][3] SPAWNCHIMERA was first reported in April 2024.[2] SPAWNCHIMERA has been observed in activity attributed to People's Republic of China (PRC) state-sponsored threat actors, including UNC5221..[4][5][2][6]

BUSHWALK is a web shell written in Perl that was inserted into the legitimate querymanifest.cgi file on compromised Ivanti Connect Secure VPNs during Cutting Edge.[1][2]

SLIGHTPULSE is a web shell that was used by APT5 as early as 2020 including against Pulse Secure VPNs at US Defense Industrial Base (DIB) entities.[1]

LIGHTWIRE is a web shell written in Perl that was used during Cutting Edge to maintain access and enable command execution by imbedding into the legitimate compcheckresult.cgi component of Ivanti Secure Connect VPNs.[1][2]

STEADYPULSE is a web shell that infects targeted Pulse Secure VPN servers through modification of a legitimate Perl script that was used as early as 2020 including in activity against US Defense Industrial Base (DIB) entities.[1]

ASPXSpy is a Web shell. It has been modified by Threat Group-3390 actors to create the ASPXTool version. [1]

PULSECHECK is a web shell written in Perl that was used by APT5 as early as 2020 including against Pulse Secure VPNs at US Defense Industrial Base (DIB) companies.[1]

Neo-reGeorg is an open-source web shell designed as a restructuring of reGeorg with improved usability, security, and fixes for exising reGeorg bugs.[1]

Operation Digital Eye was conducted in June and July of 2024 by suspected People's Republic of China (PRC)-nexus threat actors targeting business-to-business IT service providers in Southern Europe. Operation Digital Eye activity included the use of Visual Studio Code tunnels for command and control (C2) and custom lateral movement capabilities. Overlaps in tooling between Digital Eye and previous China-nexus campaigns, Operation Soft Cell and Operation Tainted Love, indicate the potential use of shared vendors or digital quartermasters.[1]

The SharePoint ToolShell Exploitation campaign was conducted in July 2025 and encompassed the first waves of exploitation against incompletely patched spoofing (CVE-2025-49706) and remote code execution (CVE-2025-49704) vulnerabilities affecting on-premises Microsoft SharePoint servers. Later patched and updated as CVE-2025-53770 and CVE-2025-53771, the ToolShell vulnerabilities were widely exploited including by China-based ransomware actor Storm-2603 and espionage actors Threat Group-3390 and ZIRCONIUM. SharePoint ToolShell Exploitation targeted multiple regions and industries including finance, education, energy, and healthcare across Asia, Europe, and the United States.[1][2][3][4][5]

C0017 was an APT41 campaign conducted between May 2021 and February 2022 that successfully compromised at least six U.S. state government networks through the exploitation of vulnerable Internet facing web applications. During C0017, APT41 was quick to adapt and use publicly-disclosed as well as zero-day vulnerabilities for initial access, and in at least two cases re-compromised victims following remediation efforts. The goals of C0017 are unknown, however APT41 was observed exfiltrating Personal Identifiable Information (PII).[1]

The 2022 Ukraine Electric Power Attack was a Sandworm Team campaign that used a combination of GOGETTER, Neo-REGEORG, CaddyWiper, and living of the land (LotL) techniques to gain access to a Ukrainian electric utility to send unauthorized commands from their SCADA system.[1][2]

FrostyGoop Incident took place in January 2024 against a municipal district heating company in Ukraine. Following initial access via likely exploitation of external facing services, FrostyGoop was used to manipulate ENCO control systems via legitimate Modbus commands to impact the delivery of heating services to Ukrainian civilians.[1][2]

C0032 was an extended campaign suspected to involve the Triton adversaries with related capabilities and techniques focused on gaining a foothold within IT environments. This campaign occurred in 2019 and was distinctly different from the Triton Safety Instrumented System Attack.[1]

The AI-Assisted Breach of Mexico's Government Infrastructure is a campaign where human operators used Claude Code AI and OpenAI GPT GPT-4.1 AI to perform reconnaissance, vulnerability exploitation, privilege escalation, discovery, credential harvesting, and exfiltration operations. The attack impacted several Mexican government institutions including the Federal Tax Authority (Servicio de Administracion Tributaria), Mexico State Government (Estado de Mexico), Mexico City Civil Registry (Registro Civil de CDMX), Jalisco State Government, National Electoral Institute (Instituto Nacional Electoral), Michoacan State Government, SADM Monterrey Municipal Water Utility (Agua y Drenaje), Tamaulipas State Government, and the Mexico City Health Department (Salud CDMX). The attack resulted in the theft of large amounts of sensitive government data and civilian records. Please note that due to the breadth of this campaign, public reporting only provides select details and as a result this campaign should not be considered comprehensive.[1]

Cutting Edge was a campaign conducted by suspected China-nexus espionage actors, variously identified as UNC5221/UTA0178 and UNC5325, that began as early as December 2023 with the exploitation of zero-day vulnerabilities in Ivanti Connect Secure (previously Pulse Secure) VPN appliances. Cutting Edge targeted the U.S. defense industrial base and multiple sectors globally including telecommunications, financial, aerospace, and technology. Cutting Edge featured the use of defense evasion and living-off-the-land (LoTL) techniques along with the deployment of web shells and other custom malware.[1][2][3][4][5]

APT41 DUST was conducted by APT41 from 2023 to July 2024 against entities in Europe, Asia, and the Middle East. APT41 DUST targeted sectors such as shipping, logistics, and media for information gathering purposes. APT41 used previously-observed malware such as DUSTPAN as well as newly observed tools such as DUSTTRAP in APT41 DUST.[1]

HomeLand Justice was a disruptive cyber campaign conducted by Iranian state-affiliated actors against Albanian government networks in July and September 2022. The activity combined ransomware, wiper malware, and data leak operations. Initial access for HomeLand Justice was established as early as May 2021, and threat actors moved laterally, exfiltrated sensitive information, and maintained persistence for approximately 14 months prior to the destructive phase of the operation. Responsibility was claimed by the "HomeLand Justice" front, which framed the campaign as retaliation against the Mujahedeen-e Khalq (MEK), an Iranian opposition group with a presence in Albania. Multiple Iran-nexus groups are assessed to have participated in the campaign, including HEXANE who probed victim infrastructure.[1][2][3] A second wave of attacks was launched in September 2022 using similar tactics following public attribution of the previous activity to Iran and the severing of diplomatic ties between Iran and Albania.[3]

Leviathan Australian Intrusions consisted of at least two long-term intrusions against victims in Australia by Leviathan, relying on similar tradecraft such as external service exploitation followed by extensive credential capture and re-use to enable privilege escalation and lateral movement. Leviathan Australian Intrusions were focused on exfiltrating sensitive data including valid credentials for the victim organizations.[1]

Operation CuckooBees was a cyber espionage campaign targeting technology and manufacturing companies in East Asia, Western Europe, and North America since at least 2019. Security researchers noted the goal of Operation CuckooBees, which was still ongoing as of May 2022, was likely the theft of proprietary information, research and development documents, source code, and blueprints for various technologies. Researchers assessed Operation CuckooBees was conducted by actors affiliated with Winnti Group, APT41, and BARIUM.[1]