Office (OOXML) / .XLSM malware analysis — malicious · 50c394ef02a84f23

MALICIOUS

Office (OOXML) / .XLSM

435.8 KB Created: 2021-07-28 10:37:27 UTC Authoring application: Microsoft Excel 12.0000

MD5: e80de13534ba365f3233d49f317e301a SHA-1: 42a1c49bf79b1f10db0281fa3c8f87d62d51edfe SHA-256: 50c394ef02a84f23ef6e066f05e35ab4d94bf208432a609364a1a25dd5f4f85d

148 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The sample is an XLSM file containing a Workbook_Open macro. This macro obfuscates data by reading values from cells, concatenating them, and writing them to a file. It then uses CreateObject to execute this file. The obfuscation makes it difficult to determine the exact payload, but the technique suggests a downloader or dropper functionality. The use of Environ() and cell references for constructing commands is a common obfuscation technique.

Heuristics 5

Workbook_Open macro high OLE_VBA_WBOPEN

Workbook_Open macro
CreateObject call high OLE_VBA_CREATEOBJ

CreateObject call
Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
VBA project inside OOXML medium OOXML_VBA

Document contains vbaProject.bin — VBA macros present
Environ() call (env variable access) low OLE_VBA_ENVIRON

Environ() call (env variable access)

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas` `282e7c5cfc12e2232f2abb8c6f2ffc00cb18f5a8c1256c9e5749a18eade6b77c`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	1165 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.
`vbaProject_00.bin` `bf59a53dd8d927d509ce131652fdbc7a2996f97c233b6f989512f5eccdc83ff6`	vba-project	OOXML VBA project: xl/vbaProject.bin	9216 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.

Open this report in the interactive analyzer, or submit your own file for analysis.