Office (OLE) / .XLS malware analysis — malicious · b0ce27c966b2cb44

MALICIOUS

Office (OLE) / .XLS

42.0 KB Created: 2020-09-28 00:53:43 Authoring application: Microsoft Excel

MD5: aea3fb20f49904e41e6e4d2767c49632 SHA-1: 39a463fe0e8cfd3a82bd839303828ed67a0b1bd7 SHA-256: b0ce27c966b2cb44fb033ec0a750a6a52388202f6c1c147824376b48c9c7e73a

140 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a known technique for executing arbitrary commands. The critical heuristic OLE_XLM_DANGEROUS_FN specifically flags the use of the RUN function within the Auto_Open macro, indicating the potential to download and execute a second-stage payload. No specific family could be identified, but the technique is common for initial access.

Heuristics 3

Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME

oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN

Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN

Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_macros.txt` `b64b082a433e78918305eac9ffe18000af84fbf9e673d4cb51ef252df2f839dc`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	8115 bytes

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