{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/products/microsoft-365/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Microsoft Windows","Microsoft 365","Google Workspace"],"_cs_severities":["high"],"_cs_tags":["clickfix","malware","social-engineering","rat","infostealer","castleloader","netsupport"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eThe BackgroundFix campaign is a social engineering scheme using fake \u0026ldquo;remove your photo background\u0026rdquo; services to deliver malware. Victims are lured to malicious sites mimicking legitimate image editing tools. The sites feature fake upload interfaces, progress bars, and download buttons to appear authentic. This campaign delivers a multi-stage payload, starting with CastleLoader. CastleLoader then drops NetSupport RAT, enabling remote access for the attackers, and CastleStealer, a custom .NET stealer designed to exfiltrate browser credentials, wallet extension data, and Telegram session files. This campaign appears to be active, with multiple domains sharing the same template.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eVictim searches for an online background removal tool and lands on a malicious BackgroundFix site.\u003c/li\u003e\n\u003cli\u003eThe victim uploads an image to the fake website.\u003c/li\u003e\n\u003cli\u003eAfter clicking a checkbox, the site instructs the victim to copy a command to their clipboard.\u003c/li\u003e\n\u003cli\u003eThe copied command executes \u003ccode\u003efinger.exe\u003c/code\u003e to query \u003ccode\u003echeeshomireciple[.]com\u003c/code\u003e\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003efinger.exe\u003c/code\u003e retrieves a batch script from the C2 server.\u003c/li\u003e\n\u003cli\u003eThe batch script executes commands to download and execute further payloads.\u003c/li\u003e\n\u003cli\u003eCastleLoader is deployed, subsequently dropping NetSupport RAT and CastleStealer.\u003c/li\u003e\n\u003cli\u003eNetSupport RAT grants the attacker remote access, while CastleStealer exfiltrates sensitive data.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful attacks result in the installation of NetSupport RAT, granting attackers remote control over the compromised system. Additionally, CastleStealer exfiltrates sensitive information such as browser credentials, wallet extension data, and Telegram session files. This stolen data can be used for further malicious activities, including financial fraud, identity theft, and unauthorized access to sensitive accounts. The active nature of the campaign and the use of multiple domains suggest a broad targeting scope.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor process creation events for the execution of \u003ccode\u003efinger.exe\u003c/code\u003e with command-line arguments pointing to external domains (IOC: \u003ccode\u003echeeshomireciple[.]com\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule to detect the execution of \u003ccode\u003efinger.exe\u003c/code\u003e to identify potential initial access attempts.\u003c/li\u003e\n\u003cli\u003eBlock the C2 domain \u003ccode\u003echeeshomireciple[.]com\u003c/code\u003e at the DNS resolver to prevent initial payload delivery.\u003c/li\u003e\n\u003cli\u003eMonitor network connections for NetSupport RAT C2 communications on port 688 to detect compromised systems (IOCs: \u003ccode\u003eporonto[.]com:688\u003c/code\u003e, \u003ccode\u003egiovettiadv[.]com:688\u003c/code\u003e).\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-30T13:00:00Z","date_published":"2026-04-30T13:00:00Z","id":"/briefs/2026-04-clickfix-backgroundfix/","summary":"The 'BackgroundFix' ClickFix campaign uses social engineering to trick victims into downloading malware disguised as a free image-editing tool, leading to the deployment of CastleLoader, NetSupport RAT for remote access, and CastleStealer for credential theft.","title":"ClickFix 'BackgroundFix' Campaign Delivers CastleLoader, NetSupport RAT, and CastleStealer","url":"https://feed.craftedsignal.io/briefs/2026-04-clickfix-backgroundfix/"},{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["OneDrive","Chrome","Brave","Opera","Discord","Slack","Microsoft 365","SharePoint"],"_cs_severities":["medium"],"_cs_tags":["command-and-control","windows","threat-detection"],"_cs_type":"advisory","_cs_vendors":["Microsoft","Google","Brave Software","Opera","Discord","Slack"],"content_html":"\u003cp\u003eAdversaries may implement command and control (C2) communications that use common web services to hide their activity. This attack technique is typically targeted at an organization and uses web services common to the victim network, which allows the adversary to blend into legitimate traffic activity. These popular services are typically targeted since they have most likely been used before compromise, which helps malicious traffic blend in. This detection focuses on identifying connections from Windows hosts to a predefined list of commonly abused web services from processes running outside of typical program installation directories, indicating a potential C2 channel leveraging legitimate services. The rule aims to detect this behavior by monitoring network connections and DNS requests originating from unusual locations.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eInitial access is achieved via an unknown method (e.g., phishing, exploit).\u003c/li\u003e\n\u003cli\u003eMalware is installed on the victim\u0026rsquo;s system, likely outside typical program directories.\u003c/li\u003e\n\u003cli\u003eThe malware establishes a DNS connection to a commonly abused web service (e.g., pastebin.com, raw.githubusercontent.com) to obscure C2 traffic.\u003c/li\u003e\n\u003cli\u003eThe malware sends encrypted or encoded commands to the web service.\u003c/li\u003e\n\u003cli\u003eThe web service acts as an intermediary, relaying the commands to the attacker\u0026rsquo;s C2 server.\u003c/li\u003e\n\u003cli\u003eThe C2 server responds with instructions, which are then relayed back to the compromised host through the same web service.\u003c/li\u003e\n\u003cli\u003eThe malware executes the received commands, potentially leading to data exfiltration, lateral movement, or other malicious activities.\u003c/li\u003e\n\u003cli\u003eThe attacker maintains persistent access and control over the compromised system using the web service as a hidden C2 channel.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation can lead to data theft, system compromise, and further propagation within the network. Since commonly used web services are utilized, the malicious activity can blend in with legitimate network traffic, making it difficult to detect. The impact can range from minor data breaches to complete network compromise, depending on the attacker\u0026rsquo;s objectives and the level of access gained.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Commonly Abused Web Services via DNS\u003c/code\u003e to your SIEM to identify suspicious DNS queries to known C2 web services originating from anomalous processes.\u003c/li\u003e\n\u003cli\u003eEnable DNS query logging on Windows endpoints to provide the data source required for the Sigma rule.\u003c/li\u003e\n\u003cli\u003eReview network connection logs for processes outside standard installation directories communicating with domains listed in the \u003ccode\u003equery\u003c/code\u003e section of the Sigma rule to identify potential C2 activity.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the potential impact of compromised hosts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-04T12:00:00Z","date_published":"2024-01-04T12:00:00Z","id":"/briefs/2024-01-04-c2-web-services/","summary":"This rule detects command and control activity using common web services by identifying Windows hosts making DNS requests to a list of commonly abused web services from processes outside of known program locations, potentially indicating adversaries attempting to blend malicious traffic with legitimate network activity.","title":"Detection of Command and Control Activity via Commonly Abused Web Services","url":"https://feed.craftedsignal.io/briefs/2024-01-04-c2-web-services/"},{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Microsoft 365"],"_cs_severities":["medium"],"_cs_tags":["suspicious-email","phishing","microsoft365"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eThis threat involves malicious or suspicious emails, as identified by Microsoft Defender for Office 365, being delivered to user mailboxes despite the existing security mechanisms. This can occur due to various factors, including misconfigured security policies, sophisticated attacker techniques that evade detection, or delayed signature updates. The delivery of such emails presents a significant risk, as they may contain spearphishing attachments, malicious links, or other harmful content designed to compromise user accounts or systems. Successful exploitation can lead to data theft, malware infection, and further propagation of the attack within the organization. It\u0026rsquo;s crucial to investigate these instances promptly to remediate any potential damage and improve email security posture.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a spearphishing email designed to bypass standard security filters.\u003c/li\u003e\n\u003cli\u003eThe email is sent to a target user within the Microsoft 365 environment.\u003c/li\u003e\n\u003cli\u003eMicrosoft Defender for Office 365 analyzes the email and identifies it as suspicious but fails to block delivery.\u003c/li\u003e\n\u003cli\u003eThe email is delivered to the user\u0026rsquo;s Inbox or Junk folder.\u003c/li\u003e\n\u003cli\u003eThe user opens the email and clicks on a malicious link or opens a malicious attachment (e.g., a macro-enabled document).\u003c/li\u003e\n\u003cli\u003eThe link redirects the user to a credential harvesting site, or the attachment executes malicious code (e.g., via PowerShell).\u003c/li\u003e\n\u003cli\u003eThe attacker gains access to the user\u0026rsquo;s account or system.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the compromised account to further propagate the attack, exfiltrate data, or deploy malware within the organization.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eThe impact of this threat can be significant. Successful exploitation can lead to the compromise of user accounts, data theft, malware infection, and financial loss. Organizations may experience business disruption, reputational damage, and legal liabilities. The number of affected users and the extent of the damage will depend on the attacker\u0026rsquo;s objectives and the organization\u0026rsquo;s security controls.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule provided to detect suspicious email delivery events within your Microsoft 365 environment and tune for your specific environment.\u003c/li\u003e\n\u003cli\u003eInvestigate any alerts generated by the Sigma rule to determine the root cause of the bypass and remediate any potential damage.\u003c/li\u003e\n\u003cli\u003eReview and adjust Microsoft Defender for Office 365 settings to improve detection accuracy and blocking capabilities.\u003c/li\u003e\n\u003cli\u003eEducate users about the risks of phishing emails and encourage them to report suspicious messages.\u003c/li\u003e\n\u003cli\u003eMonitor the \u003ccode\u003eTIMailData\u003c/code\u003e operation within the M365 audit logs for further analysis and threat hunting.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"/briefs/2024-01-m365-suspicious-email/","summary":"This brief outlines a threat where Microsoft Defender for Office 365 identifies an email as malicious or suspicious but still delivers it to a user's inbox or junk folder, potentially bypassing initial security measures.","title":"Microsoft 365 Suspicious Email Delivery","url":"https://feed.craftedsignal.io/briefs/2024-01-m365-suspicious-email/"}],"language":"en","title":"CraftedSignal Threat Feed — Microsoft 365","version":"https://jsonfeed.org/version/1.1"}