Office (OLE) / .XLS malware analysis — malicious · fc8f62a042d1159e

MALICIOUS

Office (OLE) / .XLS

61.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel

MD5: 8ab75ef0d0bd7da3de378af7dfac9116 SHA-1: 76b4b5db1c5bbbbb5b15206655246e615b17a9c6 SHA-256: fc8f62a042d1159e347a0108a72bd4a5c11f6f554a3f03113e7b0d7b3fe99a68

160 Risk Score

Malware Insights

MITRE ATT&CK

T1204.002 Malicious File T1059.005 Service Execution T1218.010 Regsvr32

The sample is an Excel 4.0 macro-enabled spreadsheet that impersonates DocuSign to lure the user into enabling macros. Upon enabling, it uses the 'regsvr32.exe -s C:\LotWin\LotWin2\Horsew.dll' command to execute a DLL. The presence of an Auto_Open macro and the explicit command line strongly indicate a downloader or initial execution stage.

Heuristics 5

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.
LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND

Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
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.
Macro/content-enable lure medium SE_ENABLE_LURE

Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
Document signing service impersonation lure medium SE_DOCUSIGN_LURE

Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_macros.txt` `4079806a1b1fa296c2735db3069c61e447d1fa3bd6d0b3662d0154f45cf6906e`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	2103 bytes

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