TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses Telegram Bot API for C2 Against Middle East Governments

TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses (TL-2026-1582), also tracked as TELESHIM Campaign, is a high-severity malware campaign, first published 2026-07-21. It has no confirmed attribution, affects Microsoft Windows (unspecified versions), maps to 27 MITRE ATT&CK techniques (T1001, T1008, T1016), and is covered by 9 detection rules and 31 indicators of compromise.

Key facts for TL-2026-1582

Threat ID
TL-2026-1582
Also known as
TELESHIM Campaign, MIXEDKEY Loader Campaign, BINDCLOAK Implant Campaign
Severity
HIGH
Status
ACTIVE
Category
MALWARE
First published
2026-07-21
Last reviewed
2026-07-21
Attribution confidence
MEDIUM
Motivation
ESPIONAGE
Target sectors
government administration
Target regions
Middle East
Detection rules
9
Indicators of compromise
31

Malware and tooling in TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

Malware and tooling: BINDCLOAK, MIXEDKEY, TELESHIM, Telegram Bot API (api.telegram.org)

A suspected East Asia-linked threat actor targeted Middle East government entities in a multi-stage intrusion (July 7-9, 2026) delivering the TELESHIM backdoor, MIXEDKEY reflective loader, and BINDCLOAK C2 implant. TELESHIM abuses the Telegram Bot API for encrypted HTTPS polling C2, validates commands against a victim's MAC address, and uses hypervisor/CPUID, WMI RAM, and I/O-stress anti-sandbox checks alongside control-flow-flattened and mixed-boolean-arithmetic obfuscation.

How TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses works

Zscaler ThreatLabz identified a previously undocumented, multi-stage malware campaign targeting Middle East government entities, assessed with moderate-to-high confidence as operated out of East Asia based on attacker IP geolocation, Windows locale configuration, and an operational window tightly bounded to 04:00-12:00 UTC (peak 07:00-11:00 UTC) during July 7-9, 2026.

Initial access is via a weaponized ISO disguised as diplomatic documents (e.g. 'Cooperation protocol for the exploration of petroleum and gas (English)' and 'Agreement on Common Border Offices (English)'), which contains a legitimate ASUSTek-signed executable (RegSchdTask.exe, renamed shimgen.exe) that DLL-sideloads a malicious AsTaskSched.dll — the TELESHIM first-stage backdoor.

TELESHIM is a 32-bit C++ DLL compiled in July 2026 that installs a 7-byte inline hook at offset 0x1394 in the host process (using VirtualProtect to alter memory permissions) to redirect execution to its payload. It checks a mutex named '\----WebKitFormBoundary7MA4YWxkTrZu0g' to prevent re-infection, and applies two string-encryption schemes: per-string XOR keys wrapped in control-flow-flattened decryption routines, and Base64-then-rolling-XOR (44-byte key) for network-related strings. Before beaconing, TELESHIM performs three anti-analysis checks: an I/O stress test (~1GB written/read across 1,000 iterations to %TEMP%\CVR9EEA.tmp to stall emulated sandboxes), a CPUID (EAX=1) hypervisor check (terminates if ECX bit 31 is set), and a WMI RAM-speed query (`wmic memorychip get speed`) that terminates execution if the value is zero/undefined. Persistence is established by copying the legitimate binary and malicious DLL into C:\programdata\shimgen_Data\ and registering a scheduled task named 'shimgen' that re-executes every 6 minutes.

C2 is conducted entirely over the Telegram Bot API (api.telegram.org), polling `/bot<TOKEN>/getUpdates?offset=<N>` with a spoofed macOS Safari User-Agent. The malware retrieves the victim's MAC address via GetAdaptersInfo for identification; the control message '13' triggers MAC registration with the operator, while other inbound messages are validated against the registered MAC and executed as shell commands via cmd.exe /C, or trigger file retrieval via `/bot<TOKEN>/getFile?file_id=<FILE_ID>` followed by rolling-XOR decryption and execution.

During the observed intrusion window, the operator ran standard reconnaissance (net user, tasklist, hostname, ipconfig /all, ipconfig /displaydns, netstat -ano, directory listings of C:\Users and staging paths under C:\ProgramData), then deployed a second persistence mechanism — a scheduled task named 'Feedback' every 10 minutes launching C:\ProgramData\Intel\winProAlertService.exe — and staged the MIXEDKEY second-stage loader by sideloading a malicious pthreadVC2.dll next to a legitimate GoPro binary (GoProAlertService.exe) alongside genuine MSVCP120.dll/MSVCR120.dll.

MIXEDKEY is a 64-bit reflective DLL loader that reconstructs its internal strings using ~1,000 mixed-boolean-arithmetic instructions per byte, assembled out of order. It implements environmental keying so the final BINDCLOAK payload only decrypts on the intended victim: it retrieves the machine's volume serial number via GetVolumeInformationA, derives a 20-byte rolling XOR key by repeating that serial 5 times, reads the encrypted payload from C:\ProgramData\Crypto\DSS\C99F29AC08454855B3D538960BB2F34F.PCPKEY (a filename that spoofs the Microsoft Platform Crypto Provider), decrypts a first layer using the file's own leading 311 bytes as a rolling XOR key, decrypts a second layer with the volume-serial-derived key, strips the MZ signature/size-prefix header, and reflectively loads the resulting PE — the BINDCLOAK C2 implant, which communicates with cert.hypersnet[.]com. Operators also pinged ssl.blsouqs[.]com and contacts.ftabnews[.]com from compromised hosts, suggesting additional or fallback infrastructure. ThreatLabz has not attributed the activity to a known APT group and has reserved a deep-dive on BINDCLOAK's C2 protocol for a follow-up (Part 2) report not yet published at time of writing.

MITRE ATT&CK techniques used in TL-2026-1582

Command and Control

T1001 Data Obfuscation; T1008 Fallback Channels; T1071 Application Layer Protocol; T1090 Proxy; T1102 Web Service; T1105 Ingress Tool Transfer; T1573 Encrypted Channel

Discovery

T1016 System Network Configuration Discovery; T1033 System Owner/User Discovery; T1049 System Network Connections Discovery; T1057 Process Discovery; T1082 System Information Discovery; T1083 File and Directory Discovery; T1497 Virtualization/Sandbox Evasion

Defense Evasion

T1027 Obfuscated Files or Information; T1036 Masquerading; T1055 Process Injection; T1140 Deobfuscate/Decode Files or Information; T1218 System Binary Proxy Execution; T1497 Virtualization/Sandbox Evasion; T1574 Hijack Execution Flow; T1620 Reflective Code Loading

Execution

T1053 Scheduled Task/Job; T1059 Command and Scripting Interpreter; T1106 Native API; T1204 User Execution

Persistence

T1053 Scheduled Task/Job

Privilege Escalation

T1053 Scheduled Task/Job

Initial Access

T1133 External Remote Services; T1566 Phishing

stealth

T1574 Hijack Execution Flow

Affected products and versions in TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

  • Microsoft — Windows (unspecified versions)
    Vulnerable versions: all supported Windows versions targeted by social-engineering ISO delivery

Remediation for TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

Immediate actions

  • Block network communication to cert.hypersnet[.]com, ssl.blsouqs[.]com, and contacts.ftabnews[.]com
  • Hunt for scheduled tasks named 'shimgen' (6-minute interval) and 'Feedback' (10-minute interval) executing from C:\programdata\shimgen_Data\ or C:\ProgramData\Intel\
  • Hunt for files C:\ProgramData\Crypto\DSS\C99F29AC08454855B3D538960BB2F34F.PCPKEY and sibling GoProAlertService.exe/pthreadVC2.dll/MSVCP120.dll/MSVCR120.dll outside legitimate GoPro install paths
  • Alert on outbound HTTPS traffic to api.telegram.org from endpoints with no legitimate Telegram business use, especially repeated GET polling to /bot<token>/getUpdates
  • Isolate and forensically image any host that mounted ISO/IMG attachments themed as diplomatic 'cooperation protocol' or 'border agreement' documents

Workarounds

  • Block or restrict access to api.telegram.org at the network egress layer for endpoints that have no business justification for Telegram usage

Longer-term hardening

  • Deploy application allowlisting / code-signing enforcement to detect renamed or relocated signed binaries (RegSchdTask.exe, GoProAlertService.exe) used for DLL sideloading
  • Restrict mounting of ISO/IMG email attachments at the mail gateway for government users
  • Implement EDR behavioral detection for inline API hooking (7-byte hook patterns via VirtualProtect) and reflective PE loading
  • Deploy network-layer detection/blocking of Telegram Bot API traffic as an approved C2 channel for high-sensitivity environments
  • Baseline and alert on anomalous scheduled task creation intervals (sub-15-minute recurring tasks) on government endpoints

Weaknesses (CWE) in TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

CWE-506, CWE-79, CWE-427

Timeline of TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

  • Two earlier TELESHIM (AsTaskSched.dll / dlpprem64.dll) instances compiled in 2025, indicating the malware family and DLL-sideloading tradecraft predate the July 2026 operation by roughly a year.
  • Newest TELESHIM (AsTaskSched.dll) sample compiled in July 2026, indicating active campaign preparation just prior to observed operations.
  • Threat actor post-compromise activity begins against Middle East government targets; command execution restricted to a 04:00-12:00 UTC daily window across the campaign.
  • Operator conducts system/network reconnaissance (net user, tasklist, ipconfig, netstat) and stages MIXEDKEY loader via GoProAlertService.exe/pthreadVC2.dll sideloading; 'Feedback' scheduled task registered for 10-minute persistence.
  • Observed threat actor operational activity window concludes; across July 7-9, activity was heavily concentrated in the 07:00-11:00 UTC sub-window each day.
  • Zscaler ThreatLabz publishes Part 1 technical analysis ('Targeted Attack on Government Entities in the Middle East') disclosing TELESHIM, MIXEDKEY, and the campaign's attack chain, IOCs, and infrastructure.
  • ThreatLabz reserves detailed technical analysis of the BINDCLOAK C2 implant's protocol for a forthcoming Part 2 report, not yet published at time of writing.
  • GBHackers coverage of the campaign ingested into the Threadlinqs hunt pipeline as TL-2026-1582.
  • GBHackers and CyberPress publish news coverage summarizing the ThreatLabz findings and DLL sideloading tradecraft; Security Boulevard mirrors the ThreatLabz Part 1 writeup.

Sources cited for TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

Threats related to TELESHIM/MIXEDKEY/BINDCLOAK Multi-Stage Malware Chain Abuses

Detection coverage for TL-2026-1582

As of 2026-07-21, Threadlinqs Intelligence publishes 9 detection rule(s) for TL-2026-1582 across Splunk SPL, Microsoft KQL and Sigma, covering 31 indicator(s) of compromise. The whole corpus is readable without an account; a free account unlocks full detection query text in Splunk SPL, Microsoft KQL and Sigma; paid tiers add raw indicator values, correlation and the MCP server. Threadlinqs MCP server · View plans.

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