Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 cd513f5d64cbabce…

MALICIOUS

Office (OLE) / .XLS

54.5 KB Created: 2020-10-26 09:32:25 Authoring application: Microsoft Excel
MD5: 28d9d9e2bde025ebc398017c245de6e5 SHA-1: 57e02730af2bd5ebc88a22fa2d322c743044d79f SHA-256: cd513f5d64cbabcef483e716e5bdf9a0a5bb9df769fbb4f62907985096088e40
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_AUTOOPEN_DEFINEDNAME heuristics. The OLE_XLM_DANGEROUS_FN heuristic firing with 'RUN=0' suggests the macro attempts to execute external commands. The OLE_XLM_ENVIRONMENT_EVASION_HALT heuristic indicates the macro may attempt to evade analysis. No specific IOCs were extracted, but the presence of these heuristics strongly suggests a malicious intent to execute arbitrary code.

Heuristics 4

  • 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.
  • XLM Auto_Open environment-evasion HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • 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.

FilenameKindSourceSize
xlm_macros.txt
171ea1b0eba1602f5e1f752e2ff04603a76a46ab0b7c58a1ea147f911c1705b6		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 16458 bytes

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