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

Static analysis result for SHA-256 3598a4f8d24a8fbf…

MALICIOUS

Office (OLE) / .XLSX

33.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-08-16
MD5: 78a8eef1db5dba3faff2bead626f205a SHA-1: dea2b77ef05fa0374377f71fb46a226a47124b2c SHA-256: 3598a4f8d24a8fbf222fff1b413c7b8409a0f7e099a37c0b1476c6928e76e688
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.003 Windows Command Shell T1566.002 Spearphishing Attachment T1059.005 Visual Basic

The Workbook_Open macro is designed to execute a batch script, Outlook.bat, which is written to the Public user directory. This script appears to be obfuscated but likely downloads and executes a second-stage payload. The use of Shell() and cmd.exe calls within the VBA code strongly suggests malicious intent. The obfuscated nature of the batch script and the lack of a clear second-stage URL prevent higher confidence.

Heuristics 6

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
9aae994c2e1c1317470f797f5379b50ed17f44f406e21538b812f3b5e27660ed
vba-macro oletools.olevba.extract_macros (decoded VBA source) 5486 bytes