Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 af484c821adb6a53…

MALICIOUS

Office (OLE)

253.5 KB Created: 2020-08-05 09:17:53 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: 46054af043d9a84688ed818e3aa69983 SHA-1: 58f4e577e7d4cfa4b25b0558f7e13a656cb66b68 SHA-256: af484c821adb6a5303096d638c43bb61f7e6b18a0573b5bbfeed0b162f8581b7
180 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled document. It contains an Auto_Open macro that attempts to evade environment checks and halt execution if evasion fails. The document body claims the content is encrypted and prompts the user to 'Enable Editing' and 'Enable Content', a common social engineering tactic to bypass macro security. The macro sheet itself is named 'I3ThRl', which is likely part of the obfuscation.

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 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 262135 bytes
SHA-256: f87ab679ccdaac1c3e1a12becf79a6291d8efb2870bf50ccf114c618d0ea9f43
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  I3ThRl
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgNameX  NAMEIDX 17 
' 0018     24 LABEL : Cell Value, String Constant - bgUoBzzjF len=0 
' 0018     20 LABEL : Cell Value, String Constant - DixKa len=0 
' 0018     21 LABEL : Cell Value, String Constant - fharUA len=0 
' 0018     20 LABEL : Cell Value, String Constant - hkOJT len=0 
' 0018     20 LABEL : Cell Value, String Constant - JSEGx len=0 
' 0018     26 LABEL : Cell Value, String Constant - MpMBHowvWmx len=0 
' 0018     21 LABEL : Cell Value, String Constant - mycRPc len=0 
' 0018     20 LABEL : Cell Value, String Constant - NLuVI len=0 
' 0018     23 LABEL : Cell Value, String Constant - omQQRMeb len=0 
' 0018     21 LABEL : Cell Value, String Constant - rHwFBW len=0 
' 0018     22 LABEL : Cell Value, String Constant - WcsbozN len=0 
' 0018     20 LABEL : Cell Value, String Constant - WvTiu len=0 
' 0018     21 LABEL : Cell Value, String Constant - XbIsiF len=0 
' 0018     25 LABEL : Cell Value, String Constant - xqQbfjiJtd len=0 
' 0018     20 LABEL : Cell Value, String Constant - xwXXC len=0 
' 0018     28 LABEL : Cell Value, String Constant -        hidden len=7 ptgRef3d  Sheet!R6925 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Con
... (truncated)