Macro-Enabled Document Malware Investigation

When You See This

1. 1

   XDR alert for WINWORD.EXE or EXCEL.EXE spawning PowerShell, cmd.exe, wscript.exe, or mshta.exe

2. 2

   Email security flags a macro-enabled document (.docm, .xlsm, .dotm) or password-protected archive attachment

3. 3

   Endpoint detection triggers on VBA macro execution followed by network connection to an external host

4. 4

   Process tree shows Office application → script interpreter → download cradle pattern

Investigation Steps

1. 1

   Analyze the process tree

   Examine the full process chain starting from the Office application. The classic pattern is: Outlook → Word/Excel → PowerShell/cmd.exe → malware payload. Document the exact command-line arguments of each process. Encoded PowerShell commands are almost always malicious when spawned from Office applications.

   XDR

   Splunk SPLMicrosoft KQLElastic Lucene

   index=endpoint parent_process_name IN ("WINWORD.EXE","EXCEL.EXE","POWERPNT.EXE") process_name IN ("powershell.exe","cmd.exe","wscript.exe","mshta.exe","certutil.exe") | table _time, dest_host, user, parent_process_name, process_name, command_line

   Decision Point

   If: Office application spawned a script interpreter with encoded or obfuscated arguments

   Yes → Almost certainly malicious. Isolate the endpoint immediately. Decode the command to understand the payload.

   No → May be legitimate automation (Office add-ins, macros for business processes). Verify with the user and document group.

2. 2

   Trace the source document

   Identify which document triggered the macro execution. Check the file path, modification timestamps, and how it arrived on the system. Search email logs for the delivery message. Check if the document was downloaded from a URL. Get the document hash for threat intelligence lookup.

   SIEMXDR

   Splunk SPLMicrosoft KQLElastic Lucene

   index=endpoint dest_host="affected_host" file_name="*.docm" OR file_name="*.xlsm" OR file_name="*.dotm" | stats latest(_time) as last_seen by file_path, file_hash, file_name

   index=email attachment_name="*" recipient="affected_user" | sort -_time | head 20 | table _time, sender_address, subject, attachment_name, attachment_hash

3. 3

   Decode the payload and identify the malware family

   Decode any Base64 or otherwise obfuscated commands found in the process tree. Identify what the payload does: does it download a second-stage payload? Does it establish persistence? Does it connect to C2? Check the payload hash and any download URLs against threat intelligence to identify the malware family (Emotet, QakBot, IcedID, etc.).

   XDRSIEM

   Splunk SPLMicrosoft KQLElastic Lucene

   index=proxy dest_port=443 src_ip="affected_host_ip" | stats count by url, http_status, bytes_in | where bytes_in > 50000 | sort -_time

4. 4

   Check for additional victims

   Search email logs for other recipients of the same malicious document. Check by sender address, subject line, attachment hash, and sending IP. Every recipient who received the document is potentially compromised.

   SIEM

   Splunk SPLMicrosoft KQLElastic Lucene

   index=email (attachment_hash="malicious_hash" OR subject="exact_subject") | stats count by recipient, action | sort -count

5. 5

   Contain and remediate

   Isolate affected endpoints. Block the sender domain and any C2 domains/IPs. Remove the malicious document from all mailboxes. If a second-stage payload was downloaded, treat this as a broader malware incident. Check for persistence mechanisms (scheduled tasks, registry run keys, startup folders).

   XDRFirewallSIEM

Common Mistakes

1. 1

   Analyzing only the macro alert without checking email logs for other recipients of the same campaign

2. 2

   Not decoding obfuscated PowerShell commands; the decoded content reveals what the macro actually did

3. 3

   Assuming macros are blocked organization-wide without verifying; many organizations have exceptions for specific groups

4. 4

   Closing the alert after removing the document without checking for downloaded second-stage payloads or persistence

Escalation Criteria

• Second-stage payload was successfully downloaded and executed

• The malware family is identified as a known initial access broker (Emotet, QakBot, IcedID)

• Multiple users across the organization received the same malicious document

Frequently Asked Questions

Did Microsoft disable macros? Why do these attacks still work?

Microsoft began blocking macros from internet-downloaded files by default in 2022. However, attackers adapted by delivering documents inside ISO/IMG containers (which strip the "Mark of the Web"), password-protected ZIP archives, OneNote attachments, and through cloud sharing links. Many organizations also maintain macro exceptions for business-critical spreadsheets.

What was Emotet and why does it matter?

Emotet was the most successful malware distribution network in history, infecting over 1.6 million systems across 200+ countries. It pioneered macro-based delivery techniques and operated as an "initial access broker", selling access to infected networks to ransomware groups. Though disrupted by law enforcement in 2021, it resurrected in 2022 and its techniques remain widely copied.

How do I practice macro malware investigations?

SOCSimulator includes scenarios with realistic Office-spawned process alerts. Practice tracing process trees and decoding obfuscated payloads in a safe environment. Start free forever.