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

Static analysis result for SHA-256 dcde900349ef5d7d…

MALICIOUS

Office (OLE) / .XLS

192.0 KB
MD5: 3b6f731cde21dc7e126fce27bdab5f08 SHA-1: 138dd89bbcdb208bb311e730af6684dcbc382193 SHA-256: dcde900349ef5d7d8ff1ca50ee9af9f20e460cc2adb3b28f182d83412477383c
180 Risk Score

Malware Insights

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

The file is an Excel 4.0 spreadsheet containing an Auto_Open macro, indicated by multiple critical heuristic firings. The Auto_Open function is known to be used for executing malicious code upon opening the document. The presence of 'RUN=490' within the macro sheet suggests the execution of a command, which is a common technique for downloading and executing further stages of malware. The document body contains what appears to be employee data, possibly a lure to make the document seem legitimate.

Heuristics 3

  • Excel 4.0 (XLM) Auto_Open + macro sheet critical OLE_XLM_AUTOOPEN
    Workbook contains an Auto_Open / Auto_Close defined name together with an Excel 4.0 macro sheet — the canonical XLM auto-execution shape used by malware families such as Emotet and QakBot.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
9326a9d6d69049bea9d03f285778a70b7039ae7998f9beecad17745d430712cf
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 134628 bytes