Office (OLE) / .XLS malware analysis — malicious · 4b9d0c7e75cdeefd

MALICIOUS

Office (OLE) / .XLS

541.5 KB Created: 2021-07-24 09:17:42 Authoring application: Microsoft Excel

MD5: ef179dbcc5b547a01eb05d6ecdae8549 SHA-1: 4e28a5e6c2cc59ad87f20591d0f71b545fefafb2 SHA-256: 4b9d0c7e75cdeefd46c224008980a62bcd3720946cd9d6c9c494f4550cc3be8b

368 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1204.002 Malicious File T1071.001 Web Protocols T1059.001 PowerShell

The file is an Excel spreadsheet containing VBA macros. The Workbook_Open macro automatically executes upon opening, leveraging ShellExecuteA and URLDownloadToFileA. This indicates the macro's intent is to download and execute a second-stage payload from a remote source. The presence of these APIs and the auto-execution mechanism strongly suggest a malicious downloader.

Heuristics 9

Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD

Reference to URLDownloadToFile API
URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD

URLDownloadToFile in VBA
ClamAV: Xls.Malware.Valyria-10028013-0 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Xls.Malware.Valyria-10028013-0
Reference to ShellExecute API high SC_STR_SHELLEXEC

Reference to ShellExecute API
Workbook_Open macro high OLE_VBA_WBOPEN

Workbook_Open macro
VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC

Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
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 macros detected medium OLE_VBA_MACROS

Document contains VBA macro code
Environ() call (env variable access) low OLE_VBA_ENVIRON

Environ() call (env variable access)

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas` `8a00d79713db40207a61fc952e3f7d2a9041ed596f591aca73fef66fd5a2c433`	vba-macro	oletools.olevba.extract_macros (decoded VBA source)	37432 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 shell/COM execution token(s). Carved artifact contains 27 long base64-like blob(s). 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.