⭐ SOC250 – APT35 HyperScrape Data Exfiltration Tool Detected Walkthrough (EventID:212)

In this case study, I investigated a high-severity alert from the LetsDefend platform: SOC250 – APT35 HyperScrape Data Exfiltration Tool Detected

This alert simulates activity associated with APT35, an advanced threat group known for targeted cyber-espionage operations and data exfiltration campaigns.

The objective of this investigation was to determine:

• Whether the alert represented true malicious activity

• If data exfiltration occurred

• The scope of compromise

• Appropriate containment actions

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📌 Alert Overview

Initial triage began by launching the alert playbook and validating the detection logic.

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🔎 Step 1: Alert Verification

The first step was to validate whether the detection was legitimate or a false positive.

The alert context suggested suspicious mail-related activity originating from a host inside the network. Therefore, deeper log analysis was required.

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🧠 Step 2: Host Log Analysis

I navigated to the Log Management panel and filtered logs based on the host IP address.

Two critical findings emerged:

1️⃣ OS-Level Log Entry

An operating system log indicated successful access to the host device. This confirmed that authentication had occurred, raising concerns of unauthorized access.

2️⃣ Exchange Log Activity

Exchange-related logs showed abnormal behavior involving mailbox access and email retrieval.

From raw log review:

• Mail data was being programmatically downloaded.

• Activity patterns did not resemble standard user interaction.

• The host communicated with the external IP: 136.243.108.14

A reputation check revealed:

• The IP had prior abuse reports for hacking and phishing.

• Geolocation traced to Germany.

• Classified as suspicious.

This significantly strengthened the malicious hypothesis.

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🖥 Step 3: Endpoint Investigation

Next, I pivoted to Endpoint Security telemetry to inspect process-level artifacts.

Two suspicious processes were identified:

⚠️ 1. EmailDownloader.exe

This executable strongly aligns with HyperScrape’s functionality — automated email harvesting and exfiltration.

⚠️ 2. ScheduleJob -UnmanagedUpdate

This process suggested persistence or scheduled execution mechanisms, often used to maintain long-term access.

The presence of these processes confirmed:

• Unauthorized mailbox scraping

• Automated data collection

• Likely staging for exfiltration

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🎯 Step 4: Reconnaissance Classification

Based on the observed activity, the attacker’s objective appeared to be intelligence gathering.

Using the MITRE ATT&CK framework, the activity aligns with:

• Gather Victim Identity Information

• Email harvesting

• Credential or mailbox enumeration

This behavior is consistent with Advanced Persistent Threat (APT) tradecraft — stealthy, intelligence-driven, and persistent.

Answer: Gather Victim Identity Information.

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🌍 Step 5: Attacker Ip Analysis

The suspicious IP (136.243.108.14) was analyzed:

• External origin (Germany)

• Previously reported for malicious activity

• No legitimate business justification for communication

Answer: External

Answer: Yes, ip is auspicious

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📊 Step 6: Scope Determination

A broader review of logs and network activity was conducted to determine lateral movement.

Findings:

• No additional hosts exhibited similar indicators.

• No evidence of widespread propagation.

• Activity isolated to a single compromised device.

Scope assessment: Contained to one host.

Answer: NO

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🛑 Step 7: Containment

Given:

• Confirmed malicious process execution

• Suspicious Exchange activity

• External C2-style communication

• Evidence of data harvesting

The affected host was immediately contained to prevent:

• Further data exfiltration

• Lateral movement

• Credential abuse

Containment was necessary and justified.

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🧾 Artifacts Collected

During the investigation, the following artifacts were documented:

• Suspicious external IP address

• Exchange log entries

• OS authentication logs

• EmailDownloader.exe process

• ScheduleJob -UnmanagedUpdate process

Proper artifact documentation ensures reproducibility and auditability of the investigation.

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📝 Analyst Notes & Documentation

Clear analyst notes were added to the case, detailing:

• Timeline of compromise

• Indicators of Compromise (IOCs)

• Process behavior analysis

• Infrastructure reputation findings

• Containment justification

Strong documentation is critical in real-world SOC operations for escalation, compliance, and threat intelligence sharing.

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✅ Final Verdict

This alert was a true positive.

Evidence confirms:

• Unauthorized mailbox scraping

• Suspicious process execution

• Communication with known malicious infrastructure

• Data harvesting activity consistent with HyperScrape

The attack aligns with tradecraft attributed to APT35 and represents a targeted reconnaissance and exfiltration attempt.

All investigation steps were completed successfully, and containment actions were properly executed.