Writing Beacon Object Files: Flexible, Stealthy, and Compatible. Monday 20 December, 2021. Our colleagues over at Core Security have been doing great things with Cobalt Strike, making use of it in their own engagements. They wrote up this post on creating Cobalt Strike Beacon Object Files using the MinGW compiler on Linux.These commands run Cobalt Strike’s SSH client. The client will report any connection or authentication issues to the parent Beacon. If the connection succeeds, you will see a new session in Cobalt Strike’s display. This is an SSH session. Right-click on this session and press Interact to open the SSH console.Recipe 24: Picking a random letter from a six-byte string. Recipe 25: Creating a Wifi QR code. Recipe 26: Extracting and Decoding a Multistage PHP Webshell. Recipe 27: Decoding an Auto Visitor PHP script. Recipe 28: De-obfuscation of Cobalt Strike Beacon using Conditional Jumps to obtain shellcode. The Cobalt Strike Arsenal Kit is a collection of customizable tools that enable users to better simulate real-world adversary tactics and techniques. Users can build and use the kits as they are or modify them to suit their engagements and support their goals. The Arsenal Kit includes: The Sleep Mask Kit – Hides Beacon in memory while it sleeps. Virus check your devices using Norton Power Eraser if applicable or any of the antivirus checks that Norton supply for mobile devices. Do search for topics such as Cobalt Strike "Beacon". When I did this I saw a response by a Microsoft independent advisor who advised steps such as scanning devices and reporting the originator of the …The Cobalt Strike Beacon that we saw is fileless, meaning that the PowerShell script injects the Beacon straight into memory and never touches disk. Once a Cobalt Strike Beacon is present on a device, the attacker has significant capability to perform additional actions including stealing tokens and credentials for lateral movement. These commands run Cobalt Strike’s SSH client. The client will report any connection or authentication issues to the parent Beacon. If the connection succeeds, you will see a new session in Cobalt Strike’s display. This is an SSH session. Right-click on this session and press Interact to open the SSH console. Cobalt Strike is a legitimate, commercial penetration testing tool that has been largely co-opted by ransomware gangs to launch attacks. It deploys an agent named “Beacon” on the targeted machine, which provides the attacker a strong foothold of attack functionality. Its use exploded among cybercriminals in 2021.Jul 29, 2015 · Cobalt Strike 2.5 also adds reverse port forwarding. Beacon’s new rportfwd command will bind a port of your choice on a compromised target. When someone connects to this port, Cobalt Strike’s team server will establish a connection to a forward host and port of your choosing. It will then relay traffic, via Beacon, between this new ... Exploring Cobalt Strike’s Beacon instructions. All the evidence suggests that beacon.dll is the Cobalt Strike Beacon malware. To understand what this malware is capable of; we analysed the DLL further. At the core of beacon.dll is a large switch statement containing cases to handle the client-side execution of C2 commands, shown in Figure 9. Cobalt Strike is popular with threat actors since it's easy to deploy and use, plus its ability to avoid detection. ... The main payload of Cobalt Strike is called “Beacon.” The Beacon payload is used to model advanced APT malware, and can do the following: Receive commands (either passively or from an interactive console) Egress ...This post, from Ernesto Alvarez Capandeguy of Core Security’s CoreLabs Research Team, describes techniques used for creating UDP redirectors for protecting Cobalt Strike team servers. This is one of the recommended mechanisms for hiding Cobalt Strike team servers and involves adding different points which a Beacon can contact for …Nov 18, 2020 · Cobalt Strike, though, hides shellcode over a named pipe. ... The Malleable C2 module in Cobalt Strike is an advanced tool that allows attackers to customize beacon traffic and create covert ... Cobalt Strike Beacon. Posted: 12-Jan-2023 | 8:27AM · 0 Replies · Permalink. Today (12th January '23) a threatening, but ultimately impotent email sender, … The Cobalt Strike Arsenal Kit is a collection of customizable tools that enable users to better simulate real-world adversary tactics and techniques. Users can build and use the kits as they are or modify them to suit their engagements and support their goals. The Arsenal Kit includes: The Sleep Mask Kit – Hides Beacon in memory while it sleeps. Works with Cobalt Strike Beacon The demo uses metasploit's meterpreter payload, but I have tested this technique with Cobalt Strike beacon and it also bypasses the Windows Defender. Overview. The technique that allowed me to bypass Windows Defender is simple: Victim machine (10.0.0.7) opens up a listening TCP socket on on …Oct 19, 2023 · The Cobalt Strike Beacon scam email utilizes various sophisticated social engineering and pressure tactics to manipulate and deceive victims. Here is how it operates, step-by-step: The email will have an alarming or urgent subject line designed specifically to entice opening and reading. Cobalt Strike is popular with threat actors since it's easy to deploy and use, plus its ability to avoid detection. ... The main payload of Cobalt Strike is called “Beacon.” The Beacon payload is used to model advanced APT malware, and can do the following: Receive commands (either passively or from an interactive console) Egress ...May 28, 2021 · This report provides detailed analysis of three malicious ISO files associated with a spearphishing campaign using Constant Contact. The files contain a custom Cobalt Strike Beacon loader, a decoy PDF, and a shortcut that executes the beacon on a compromised system. i春秋. 上周更新了Cobalt Strike系列教程第一章：简介与安装，文章发布后，深受大家的喜爱，遂将该系列教程的其他章节与大家分享，提升更多实用技能！. 第二章：Beacon详 …Short bio. Trojan is Malwarebytes’ detection name that applies to various types of malware that hide their true intentions and then exploit systems once they are inside.. Type and source of infection. Common infection methods for Trojans include:It is often difficult to collect the Cobalt Strike beacon payload from memory and extract its configuration to identify observables and cluster group activities, partially due to the tremendous amount of metadata the beacon’s configurations include. The early stages of an intrusion usually include initial access, execution, persistence, and ... Cobalt Strike support resources, including the Cobalt Strike Manual, Community Kit, and Technical notes are available to help users. ... Beacon; Interoperablity ... Redefine Beacon's communication with Cobalt Strike's malleable C2 language. This allows you to cloak Beacon activity to look like other malware or blend-in as legitimate traffic. The Beacon Console. Right-click on a Beacon session and select interact to open that Beacon’s console. The console is the main user interface for your Beacon session. Nov 3, 2022 · The Cobalt Strike Team Server, also known as CS Team Server, is the centralized C2 application for a Beacon and its operator (s). It accepts client connections, orchestrates remote commands to Beacon implants, provides UI management, and various other functions. Cobalt Strike allows users to obfuscate Beacon via its malleable C2 profile. For example, the stage{} block can be used to modify the RAW Beacon payload and define how it is loaded into memory. Whilst this offers flexibility, it does have limitations which can expose Beacon to detection via YARA scanning (as shown in the Cobalt Strike and …Cobalt Strike Analysis and Tutorial: Identifying Beacon Team Servers in the Wild. 74,502. people reacted. 27. 9 min. read. By Durgesh Sangvikar, Chris Navarrete, …Beacon Object Files (BOFs) were introduced in Cobalt Strike 4.1 in 2020. Since their release, BOFs have played a key role in post-exploitation activities, surpassing Reflective DLLs, .NET assemblies, and PowerShell scripts. However, in our experience, many developers struggle with four primary pain points: The limitations of writing BOFs in CCobalt Strike Beacon provides encrypted communication with the C&C server to send information and receive commands. Those commands can include instructions to download malware. After doing this, they can use Cobalt Strike to map out the network and identify any vulnerabilities as well as deploy implants, backdoors, and other tools to …These beacons send data back with an HTTP POST request. This is the default. You have incredible control over the behavior and indicators in this payload via Malleable C2. HTTP(S) Listener Setup. To create a HTTP or HTTPS Beacon listener select Cobalt Strike-> Listeners on the main menu and press the Add button at the bottom of the …These beacons send data back with an HTTP POST request. This is the default. You have incredible control over the behavior and indicators in this payload via Malleable C2. HTTP(S) Listener Setup. To create a HTTP or HTTPS Beacon listener select Cobalt Strike-> Listeners on the main menu and press the Add button at the bottom of the …Cobalt Strike "Beacon" : PHISHING OR EXTORTION ? I have multiple email addresses for miscellaneous purposes, and I did not receive other threats on these emails, at least for now if true. DE: withheld @479644105645826333.com. Objet : Payment Report - 224145-1380-*. À : withheld.Port 4444 is the default port for Metasploit, another hacking platform which is often seen in conjunction with Cobalt Strike beacon. It then presented the human analysts with a full list of compromised hosts. Figure 3: Cyber AI Analyst summary of an affected host using non-standard ports for C2 and subsequently scanning the network.May 16, 2019 · This is a detection for Cobalt Strike Beacon, which is a software component that gets deployed in target devices and allows an attacker remote access to the device to perform various tasks. The first two rely on named pipe impersonation. The last one relies on token duplication. 1. meterpreter > getsystem -h. 2. Usage: getsystem [options] 3. 4. Attempt to elevate your privilege to that of local system.We would like to show you a description here but the site won’t allow us.Learn how to identify and detect adversary activities using Cobalt Strike's Beacon client agent, a tool for post-exploitation and red team operations. The blog explains the behavior, commands, and …From Beacon to Interactive RDP Session. Lateral Movement, Tunnelling, Firewall Evasion. This is a quick note showing how to get an interactive Remote Desktop Session (RDP) session from a Cobalt Strike beacon by leveraging socks proxy and proxychains.Oct 19, 2023 · The Cobalt Strike Beacon scam email utilizes various sophisticated social engineering and pressure tactics to manipulate and deceive victims. Here is how it operates, step-by-step: The email will have an alarming or urgent subject line designed specifically to entice opening and reading. Cobalt Strike support resources, including the Cobalt Strike Manual, Community Kit, and Technical notes are available to help users. ... Beacon; Interoperablity ... Cobalt Strike is commercial threat emulation software that emulates a quiet, long-term embedded actor in a network. This actor, known as Beacon, communicates …Most common watermark. Unsurprisingly most common watermark was 0. The watermark of 0 is indicative of cracked versions for Cobalt Strike which are commonly used by threat actors in their campaigns. More interestingly is 305419896, 1359593325, and 1580103814, all had configuration counts above 100. The watermark 305419896 has …Jun 1, 2021 · Cobalt Strike Beacon provides encrypted communication with the C&C server to send information and receive commands. Those commands can include instructions to download malware. After doing this, they can use Cobalt Strike to map out the network and identify any vulnerabilities as well as deploy implants, backdoors, and other tools to accomplish ... A complementary strategy to the Host Rotation Strategy was introduced to Cobalt Strike 4.5. The max retry strategy was added to HTTP, HTTPS, and DNS beacon listeners. A max retry strategy allows a beacon to exit after a specified failure count. As the failure count increases, sleep is adjusted to a specified value. By default, sleep is …The UDRL is an important aspect of Cobalt Strike’s evasion strategy. Cobalt Strike achieves “evasion through flexibility”, meaning we give you the tools you need to modify default behaviors and customize Beacon to your liking. This was something that Raphael Mudge felt strongly about and will remain a key part of the Cobalt Strike ...Exceptions to the 4.5 process injection updates Process Injection Spawn (Fork & Run) The PROCESS_INJECT_SPAWN hook is used to define the fork&run process injection technique. The following Beacon commands, aggressor script functions, and UI interfaces listed in the table below will call the hook and the user can implement their …Last updated April 19, 2024 Views 72,356 Applies to: Windows. /. Windows 11. /. Security and privacy. I received an email today, stating that someone or group had …Cobalt Strike 2.5 uses the SMB Beacon to help with this problem. Beacon features to include its Bypass UAC attack and new spawnas command [use credentials to spawn a payload; without touching disk] accept the SMB Beacon as a target payload. This greatly improves Cobalt Strike’s options to work through one egress channel.Cobalt Strike will even tab complete your aliases for you. You should see Hello World! in the Beacon console. You may also use the &alias function to define an alias. Cobalt Strike passes the following arguments to an alias: $0 is the alias name and arguments without any parsing. $1 is the ID of the Beacon the alias was typed from.SentinelOne discovered a denial of service (DoS) vulnerability in Cobalt Strike. The bug (aka Hotcobalt) can cause a denial of service on a teamserver by using a fake beacon sending abnormally large screenshots.. This bug has been fixed in Cobalt Strike 4.4. Consider mitigating this risk to a teamserver by hardening your C2 infrastructure.Jan 20, 2022 · These two articles ( [ 1] [ 2 ]) are ideal for helping security analysts identify, collect, and configure Cobalt Strike beacon payloads from an endpoint using Elastic. It is often difficult to collect the Cobalt Strike beacon payload from memory and extract its configuration to identify observables and cluster group activities, partially due to ... Aug 4, 2021 · The threat actor also installed Cobalt Strike PowerShell stagers on servers accessed when moving laterally through the compromised network. These stagers allowed the Cobalt Strike Beacon payload to execute in memory. Cobalt Strike PowerShell stager's default execution pattern is always configured to launch as a service and is invoked from the ... The Cobalt Strike Beacon that we saw is fileless, meaning that the PowerShell script injects the Beacon straight into memory and never touches disk. Once a Cobalt Strike Beacon is present on a device, the attacker has significant capability to perform additional actions including stealing tokens and credentials for lateral movement.Richard noted that threat actors shifted away from popular backdoors such as Cobalt Strike Beacon over the last three years. "This likely is related to attackers …Cobalt Strike is a well-known beacon or post-exploitation tool that has been linked to ransomware families like Ryuk, DoppelPaymer, and Povlsomware. The Cobalt Strike variant used here follows its typical …DNS - using a variety of DNS queries, Cobalt Strike's beacons can communicate back to the C2 server using only DNS. The advantage is that name resolution is almost always allowed and no direct communication takes place between the implant and the C2 server, since the DNS resolution will happen using the default nameservers. ...Cobalt Strike can use PowerShell, .NET, and Reflective DLLs for its post-exploitation features. This is the weaponization problem set. How to take things, developed outside the tool, and create a path to use them in the tool. One of the newest weaponization options in Cobalt Strike are Beacon Object Files.Tuesday 16 May, 2023. Over the past few years, there has been a massive proliferation of YARA signatures for Beacon. We know from conversations with our customers that this has become problematic when using Cobalt Strike for red team engagements and that there has been some confusion over how Cobalt Strike’s malleable C2 options can help.Many of Cobalt Strike’s attacks and workflows deliver a payload as multiple stages. The first stage is called a stager. The stager is a very tiny program, often written in hand-optimized assembly, that: connects to Cobalt Strike, downloads the Beacon payload (also called the stage), and executes it. The payload staging process exists for a ...Cobalt Strike can use PowerShell, .NET, and Reflective DLLs for its post-exploitation features. This is the weaponization problem set. How to take things, developed outside the tool, and create a path to use them in the tool. One of the newest weaponization options in Cobalt Strike are Beacon Object Files.Cobalt Strike 2.5 uses the SMB Beacon to help with this problem. Beacon features to include its Bypass UAC attack and new spawnas command [use credentials to spawn a payload; without touching disk] accept the SMB Beacon as a target payload. This greatly improves Cobalt Strike’s options to work through one egress channel.Learn how to identify and detect adversary activities using Cobalt Strike's Beacon client agent, a tool for post-exploitation and red team operations. The blog explains the behavior, commands, and …Also, a Cobalt Strike beacon can execute PowerShell scripts, perform keylogging activities, take screenshots, download files, and spawn other payloads. Ways Cobalt Strike Can Help Security Researchers It is often difficult to spot gaps or vulnerabilities in a system that you created or have been using for a long time. By using …A key part of Cobalt Strike is the Beacon, a piece of software injected into the target computer to create a secret communication channel that enables the Cobalt …To Beacon, a BOF is just a block of position-independent code that receives pointers to some Beacon internal APIs. To Cobalt Strike, a BOF is an object file produced by a C compiler. Cobalt Strike parses this file and acts as a linker and loader for its contents. This approach allows you to write position-independent code, for use in Beacon ...Aug 4, 2021 · The threat actor also installed Cobalt Strike PowerShell stagers on servers accessed when moving laterally through the compromised network. These stagers allowed the Cobalt Strike Beacon payload to execute in memory. Cobalt Strike PowerShell stager's default execution pattern is always configured to launch as a service and is invoked from the ... TCP Beacon. The TCP Beacon uses a TCP socket to communicate through a parent Beacon. This peer-to-peer communication works with Beacons on the same host and across the network. TCP Listener Setup. To create a TCP Beacon listener select Cobalt Strike -> Listeners on the main menu and press the Add button at the bottom of the …In this particular case, LockBit managed to side-load Cobalt Strike Beacon through a signed VMware xfer logs command line utility. Since our initial publication of this report, we have identified a connection with an affiliate Microsoft tracks as DEV-0401. A switch to LockBit represents a notable departure in DEV-0401’s previously observed TTPs.SentinelOne discovered a denial of service (DoS) vulnerability in Cobalt Strike. The bug (aka Hotcobalt) can cause a denial of service on a teamserver by using a fake beacon sending abnormally large screenshots.. This bug has been fixed in Cobalt Strike 4.4. Consider mitigating this risk to a teamserver by hardening your C2 infrastructure.SMB Beacon. Select Beacon SMB as the Payload type and give the listener a Name. Make sure to give the new listener a memorable name as this name is how you will refer to this listener through Cobalt Strike’s commands and workflows. The only option associated with the SMB Beacon is the Pipename (C2). You can set an explicit pipename or accept ...A key part of Cobalt Strike is the Beacon, a piece of software injected into the target computer to create a secret communication channel that enables the Cobalt …These beacons send data back with an HTTP POST request. This is the default. You have incredible control over the behavior and indicators in this payload via Malleable C2. HTTP(S) Listener Setup. To create a HTTP or HTTPS Beacon listener select Cobalt Strike-> Listeners on the main menu and press the Add button at the bottom of the …Sep 21, 2020 · can protect against them. We will also look at Cobalt Strike from the adversary’s perspective. LISTENERS Listeners are at the core of Cobalt Strike. They allow adversaries to configure the C2 method used in an attack. Every attack or payload generated in Cobalt Strike requires the targeted user to select a Listener to embed within it. These commands run Cobalt Strike’s SSH client. The client will report any connection or authentication issues to the parent Beacon. If the connection succeeds, you will see a new session in Cobalt Strike’s display. This is an SSH session. Right-click on this session and press Interact to open the SSH console. Starting the Team Server. Cobalt Strike is split into client and a server components. The server, referred to as the team server, is the controller for the Beacon payload and the host for Cobalt Strike ’s social engineering features. The team server also stores data collected by Cobalt Strike and it manages logging.. The Cobalt Strike team server must run on a …Cobalt Strike 4.9 is now available. This release sees an overhaul to Cobalt Strike’s post exploitation capabilities to support user defined reflective loaders (UDRLs), the ability to export Beacon without a reflective loader which adds official support for prepend-style UDRLs, support for callbacks in a number of built-in functions, a new in-Beacon …It is time to test how well the beacon will perform against static signature scanners. Enabling the following feature will remove most of the strings stored in the beacon’s heap: set obfuscate "true"; Once the profile is applied to Cobalt Strike, generate a raw shellcode and put it in the Shellcode loader’s code. Once the EXE was compiled ...Sep 13, 2021 · Cobalt Strike is a popular red team tool for Windows which is also heavily used by threat actors. At the time of this writing, there is no official Cobalt Strike version for Linux. In August 2021, we at Intezer discovered a fully undetected ELF implementation of Cobalt Strike’s beacon, which we named Vermilion Strike. The Cobalt Strike beacon allows the threat actors to execute commands remotely on the infected device, allowing threat actors to steal data or spread laterally through the compromised network.Threat Spotlight Cobalt Strike. Cisco Talos discovered a malicious campaign in August 2022 delivering Cobalt Strike beacons that could be used in later, follow-on attacks. Lure themes in the phishing documents in this campaign are related to the job details of a government organization in the United States and a trade union in …Cobalt Strike’s ‘Beacon’ payload is a particularly dangerous aspect of the tool. Once deployed, it allows attackers to maintain a discreet presence within a network, carrying out operations while remaining largely invisible to security systems. This facilitates long-term data theft, manipulation, and disruption of network operations.Most common watermark. Unsurprisingly most common watermark was 0. The watermark of 0 is indicative of cracked versions for Cobalt Strike which are commonly used by threat actors in their campaigns. More interestingly is 305419896, 1359593325, and 1580103814, all had configuration counts above 100. The watermark 305419896 has …
The Cobalt Strike Beacon that we saw is fileless, meaning that the PowerShell script injects the Beacon straight into memory and never touches disk. Once a Cobalt Strike Beacon is present on a device, the attacker has significant capability to perform additional actions including stealing tokens and credentials for lateral movement.. Flight sfo to london
On Wednesday, Intel 471 published a report exploring the abuse of Cobalt Strike, a commercial penetration testing tool released in 2012 which can be used to deploy beacons on systems to simulate ...Control your target’s network with Cobalt Strike ’s Beacon. This post-exploitation payload uses an asynchronous “ low and slow ” communication pattern that’s common with …Tuesday 16 May, 2023. Over the past few years, there has been a massive proliferation of YARA signatures for Beacon. We know from conversations with our customers that this has become problematic when using Cobalt Strike for red team engagements and that there has been some confusion over how Cobalt Strike’s malleable C2 options can help.Monday 20 December, 2021. The User Defined Reflective Loader (UDRL) was first introduced in Cobalt Strike 4.4. to allow the creation and use of a custom reflective loader. This quickly took off by the community and its limits were pushed. Updates were made in 4.5 to help address some of these limits.The latter is also notable for the fact that malware acts as a conduit for delivering Cobalt Strike, while the former has been used to deliver a different malware …As Google explained, cracked and leaked releases of Cobalt Strike are, in most cases, at least one version behind, which allowed the company to collect hundreds of stagers, templates, and beacon ...Cobalt Strike beacons have the ability to use named pipes to receive and send commands between beacons and spawned processes. In the logs of the infected machine, we saw a pipe created which is known to be used by Cobalt Strike beacons. EventType: CreatePipe UtcTime: 2022-04-20 11:55:03.377 ProcessGuid: {c64152da …i春秋. 上周更新了Cobalt Strike系列教程第一章：简介与安装，文章发布后，深受大家的喜爱，遂将该系列教程的其他章节与大家分享，提升更多实用技能！. 第二章：Beacon详 …Oct 19, 2023 · The Cobalt Strike Beacon scam email utilizes various sophisticated social engineering and pressure tactics to manipulate and deceive victims. Here is how it operates, step-by-step: The email will have an alarming or urgent subject line designed specifically to entice opening and reading. Wie Cobalt Strike Beacon Teil von Bedrohungskampagnen wurde. Im Dezember 2020 wurde eine umfangreiche und effektive Spionagekampagne bekannt, die eine Backdoor in die verbreitete Netzwerküberwachungssoftware SolarWinds installierte. Die Ermittler deckten auf, dass zu den von den Bedrohungsakteuren verwendeten Tools auch Cobalt …A tool to hunt/mine for Cobalt Strike beacons and "reduce" their beacon configuration for later indexing. Hunts can either be expansive and internet wide using services like SecurityTrails, Shodan, or ZoomEye or a list of IP's. Getting started. Install melting-cobalt;May 16, 2023. 08:10 AM. 2. Geacon, a Go-based implementation of the beacon from the widely abused penetration testing suite Cobalt Strike, is being used more and more to target macOS devices. Both ...Cobalt Strike Introduction. This 40 minute on-demand Cobalt Strike demonstration includes a guided walkthrough in a small cyber range to help demonstrate the key features of the solution. The focus is not on understanding all the security topics mentioned in detail, but rather to explore Cobalt Strike’s capabilities.With the ability to steal a specific one by using BeaconUseToken(HANDLE token) Cobalt Strike Beacon API. This is great but I wanted to keep track of the … Redefine Beacon's communication with Cobalt Strike's malleable C2 language. This allows you to cloak Beacon activity to look like other malware or blend-in as legitimate traffic. The Beacon Console. Right-click on a Beacon session and select interact to open that Beacon’s console. The console is the main user interface for your Beacon session. Pelaku ancaman mengimplementasikan ulang Cobalt Strike Beacon versi Linux dan Windows tidak resmi dari awal dan secara aktif menggunakannya dalam serangan yang ditujukan untuk organisasi di seluruh dunia. Versi Linux dari alat pasca-eksploitasi komersial diberi nama kode Vermilion Strike dan menurut peneliti Intezer, yang melihatnya, apakah ...As Google explained, cracked and leaked releases of Cobalt Strike are, in most cases, at least one version behind, which allowed the company to collect hundreds of stagers, templates, and beacon ...Jun 15, 2022 · Extract the package on the Windows endpoint (Password: apt). Start cmd.exe as Administrator. Navigate to the extracted program folder and run APTSimulator.bat. Once APTSimulator.bat is running, choose “CobaltStrike Beacon Simulation” and let it run. This would generate Cobalt Strike beacon activity. .