An Income Tax Assessment Notice Phishing Campaign Delivering Malware

An Income Tax Assessment Notice Phishing Campaign Delivering Malware
CYFIRMA reported a tax-themed malware campaign using a fake Indian Income Tax Department portal on harivo[.]vip to trick victims into downloading Tax_Assessment_0609.zip and staged payloads Tax_Assessment.img, Tax_Assessment.exe, and libsvcs.dll. The malware uses ConfuserEx obfuscation, reflection-based DLL loading, persistence, and encrypted C2 traffic to support RAT-like control over Windows systems, with infrastructure tied to 103[.]231[.]12[.]27:4444. #Tax_Assessment.exe #libsvcs.dll #harivovip #IncomeTaxDepartment #XWorm

Keypoints

  • The campaign impersonates the Indian Income Tax Department using a fake assessment notice hosted on harivo[.]vip.
  • Victims are lured into downloading a malicious ZIP archive named Tax_Assessment_0609.zip.
  • The infection chain uses a staged disk image, Tax_Assessment.img, which contains Tax_Assessment.exe and libsvcs.dll.
  • Tax_Assessment.exe acts as a loader and uses Assembly.LoadFrom() and reflection to execute the DLL payload.
  • Both binaries are protected with ConfuserEx and use stealth features such as hidden console windows, registry changes, and spoofed metadata.
  • libsvcs.dll provides RAT-like functions including persistence, host discovery, user activity monitoring, remote execution, and encrypted C2 communication.
  • Hardcoded infrastructure includes 103[.]231[.]12[.]27:4444, and the observed behavior resembles XWorm-like malware.

MITRE Techniques

  • [T1566.002 ] Phishing: Spearphishing Link – The fake tax portal lures victims to download the malicious archive (‘Fraudulent Income Tax website → malicious archive download’).
  • [T1189 ] Drive-by Compromise – The fake portal delivers the ZIP archive through a deceptive website (‘ZIP archive with malware delivered via fake portal’).
  • [T1204.002 ] User Execution: Malicious File – The user is prompted to download and open the malicious file (‘User downloads/executes Tax_Assessment.exe’).
  • [T1218 ] System Binary Proxy Execution – The mounted disk image stages execution of the next components (‘Mounted disk image (Tax_Assessment.img) stages execution’).
  • [T1059 ] Command and Scripting Interpreter – The loader uses reflection-based .NET execution to run the payload (‘Reflection-based .NET dynamic execution’).
  • [T1620 ] Reflective Code Loading – Tax_Assessment.exe loads libsvcs.dll with Assembly.LoadFrom() (‘Assembly.LoadFrom() loads libsvcs.dll’).
  • [T1027 ] Obfuscated/Compressed Files – ConfuserEx is used to hide the malicious code and complicate analysis (‘ConfuserEx obfuscation on EXE/DLL’).
  • [T1036 ] Masquerading – The files and portal impersonate tax documents and legitimate government communication (‘Deceptive filenames/metadata impersonating tax docs’).
  • [T1036.005 ] Match Legitimate Resource Name or Location – The DLL uses fake Microsoft-like metadata to look trusted (‘DLL metadata: “Runtime Service Host”, “Microsoft Corporation”‘).
  • [T1140 ] Deobfuscate/Decode Files – The protected assemblies are unpacked/decoded at runtime (‘Runtime decoding of protected assemblies’).
  • [T1564.003 ] Hide Artifacts: Hidden Window – The malware hides its console window during execution (‘Console window hidden during execution’).
  • [T1112 ] Modify Registry – The malware modifies registry settings for stealth and persistence (‘Registry mods for execution/persistence’).
  • [T1547.001 ] Registry Run Keys / Startup Folder – The malware uses startup registration and auto-run behavior (‘SetAutoRun, AddToStartupAdmin/NonAdmin’).
  • [T1053.005 ] Scheduled Task – Scheduled-task persistence is included in the malware’s capabilities (‘Scheduled-task persistence functionality’).
  • [T1082 ] System Information Discovery – The payload gathers OS and host information (‘GetWindowsVersion() collects OS/host details’).
  • [T1518.001 ] Security Software Discovery – The malware checks for security products (‘GetSecurityInfo() enumerates security products’).
  • [T1033 ] System Owner/User Discovery – The payload collects user information (‘User info collection during reconnaissance’).
  • [T1497.001 ] Virtualization/Sandbox Evasion – The malware performs anti-analysis checks before execution (‘Anti-analysis checks before execution’).
  • [T1071.001 ] Application Layer Protocol: Web Protocols – The C2 communication uses application-layer web communications (‘C2 via application-layer web communications’).
  • [T1573 ] Encrypted Channel – The malware uses an embedded 32-byte key for encrypted C2 (’32-byte embedded encryption key for C2′).
  • [T1105 ] Ingress Tool Transfer – Additional payload loading/execution is supported by the malware (‘Dynamic payload loading/execution’).
  • [T1219 ] Remote Access Software – The payload provides RAT-style remote access and command execution (‘RAT functionality for remote access/command execution’).

Indicators of Compromise

  • [Domain ] fraudulent tax portal and campaign hosting – harivo[.]vip, harivo.vip
  • [IP address ] hardcoded C2 server and malicious infrastructure – 103[.]231[.]12[.]27, 38[.]76[.]161[.]218
  • [File names ] staged infection-chain files – Tax_Assessment_0609.zip, Tax_Assessment.img, Tax_Assessment.exe, libsvcs.dll
  • [MD5 hashes ] sample file hashes from the campaign – 3adcf5fca3f4fe23a9b73951e20d43bc, ba036fbf209b2dbdfec3fd3dee9b1798, and 2 more hashes
  • [SHA-256 hashes ] YARA and IOC hashes associated with the campaign – 372d7d8ca222e03afa5970848cf88efa6a3bc5146d20398601285fc7eaea6735, f5dc1016679f54f2be22da0ff6642046f7a943410c188514b96c28d8a3b95e12, and 2 more hashes
  • [Port ] encrypted C2 communication endpoint – 103[.]231[.]12[.]27:4444
  • [Strings ] campaign-specific lure text used on the fake portal – Download Assessment Order & Workings, NOTICE OF ASSESSMENT


Read more: https://www.cyfirma.com/research/an-income-tax-assessment-notice-phishing-campaign-delivering-malware/