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

Static analysis result for SHA-256 068e3ae90e66282c…

MALICIOUS

Office (OLE) / .XLS

53.5 KB Created: 2020-10-28 08:15:02 Authoring application: Microsoft Excel
MD5: 0d399f4446192b90b4338229296c91a3 SHA-1: c1f8f3f6cd48e44a8e7d248071ca3af4efc111cd SHA-256: 068e3ae90e66282cfbd2c2a0b739ff014c60163f634e5b70e3001c17ce6175f6
180 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a common technique for executing malicious code. The heuristics indicate the presence of dangerous formula APIs and an environment-evasion halt gate, suggesting an attempt to run arbitrary commands or evade detection. The macro sheet itself contains obfuscated data, further supporting a malicious intent.

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
41db1271e75afb26ba50db813f5e0e7a3d03f8512f101f8c97def5a2e5c8a2c5
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 16017 bytes