Worm

What is “Worm.Esfury.A”?

Malware Removal

The Worm.Esfury.A is considered dangerous by lots of security experts. When this infection is active, you may notice unwanted processes in Task Manager list. In this case, it is adviced to scan your computer with GridinSoft Anti-Malware.

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What Worm.Esfury.A virus can do?

  • Behavioural detection: Executable code extraction – unpacking
  • SetUnhandledExceptionFilter detected (possible anti-debug)
  • Yara rule detections observed from a process memory dump/dropped files/CAPE
  • Creates RWX memory
  • Possible date expiration check, exits too soon after checking local time
  • Anomalous file deletion behavior detected (10+)
  • Guard pages use detected – possible anti-debugging.
  • A process attempted to delay the analysis task.
  • Dynamic (imported) function loading detected
  • Performs HTTP requests potentially not found in PCAP.
  • HTTPS urls from behavior.
  • Enumerates running processes
  • Expresses interest in specific running processes
  • Reads data out of its own binary image
  • A process created a hidden window
  • Attempts to modify Internet Explorer’s start page
  • CAPE extracted potentially suspicious content
  • Drops a binary and executes it
  • Unconventionial language used in binary resources: Spanish (Chile)
  • The binary likely contains encrypted or compressed data.
  • Removes Security and Maintenance icon from Start menu, Taskbar and notifications
  • Authenticode signature is invalid
  • Behavioural detection: Injection (Process Hollowing)
  • Executed a process and injected code into it, probably while unpacking
  • Behavioural detection: Injection (inter-process)
  • Creates or sets a registry key to a long series of bytes, possibly to store a binary or malware config
  • Created a process from a suspicious location
  • Steals private information from local Internet browsers
  • Network activity contains more than one unique useragent.
  • Installs itself for autorun at Windows startup
  • Overwrites multiple files with zero bytes (hex 00) indicative of a wiper
  • Attempts to modify proxy settings
  • Operates on local firewall’s policies and settings
  • Creates a copy of itself
  • Attempts to disable or modify Explorer Folder Options
  • Attempts to disable or modify the Run command from the Start menu and the New Task (Run) command from Task Manager
  • Attempts to disable System Restore
  • Attempts to disable UAC
  • The sample wrote data to the system hosts file.
  • Attempts to modify or disable Security Center warnings
  • Attempts to modify UAC prompt behavior
  • Modifies Image File Execution Options, indicative of process injection or persistence
  • Anomalous binary characteristics
  • Attempts to modify Explorer settings to prevent file extensions from being displayed
  • Attempts to modify Explorer settings to prevent hidden files from being displayed
  • Attempts to modify user notification settings

How to determine Worm.Esfury.A?


File Info:

name: EE01C35F2A8074AA4245.mlw
path: /opt/CAPEv2/storage/binaries/90cf3aeacfefdd46e77ce0785e519112ef14bbfa33a52f958af9f1da5da97143
crc32: 0E0FA919
md5: ee01c35f2a8074aa42459fe16c34a411
sha1: e5f2b5de87d0ac19ce06ff32acfe2acbf4e71f89
sha256: 90cf3aeacfefdd46e77ce0785e519112ef14bbfa33a52f958af9f1da5da97143
sha512: 80e71ee8c1f3f5e0f94ee3e8c222306ae2e9c5f001570892a9a5ba8c0c747bda4765a182ee42609072b3bd082216f1ba8ffd5aba4fde871bf847a02cfdf9cbf2
ssdeep: 1536:z0HjHkAScR9hXkYQB3k69JusuqdGiA2MvZut+pN5ULmRPYAVPlVDKmQ9x6:zWEcWY9HVX2MvktynULsPemGx6
type: PE32 executable (GUI) Intel 80386, for MS Windows
tlsh: T14B3502196C2C6931E6CE54B290D78143A8BF583CDAFBA4EB4C900AD0D2750FB5D3616F
sha3_384: 0e03f44f05e89bc24348f8b562ac5dc59c60b62efe3bd382045157b0f61c9e74fe75c9a8842f6d993eaed6d0ec39f7f6
ep_bytes: 558becb804100000e873020000a10030
timestamp: 2013-06-09 15:24:29

Version Info:

0: [No Data]

Worm.Esfury.A also known as:

BkavW32.AIDetect.malware1
Elasticmalicious (high confidence)
MicroWorld-eScanGen:Variant.Cerbu.82817
FireEyeGeneric.mg.ee01c35f2a8074aa
CAT-QuickHealWorm.Esfury.A
McAfeeW32/Worm-FNH!EE01C35F2A80
MalwarebytesMalware.AI.4141103819
SangforSuspicious.Win32.Save.a
K7AntiVirusP2PWorm ( 001eebf51 )
K7GWP2PWorm ( 001eebf51 )
Cybereasonmalicious.f2a807
BitDefenderThetaGen:NN.ZexaF.34742.ezZ@aG5iktH
SymantecSMG.Heur!gen
ESET-NOD32Win32/AutoRun.VB.XW
BaiduWin32.Trojan-Dropper.Injector.g
ClamAVWin.Trojan.Esfury-87
KasperskyHEUR:Trojan.Win32.Generic
BitDefenderGen:Variant.Cerbu.82817
NANO-AntivirusTrojan.Win32.AntiAV.cqkxpe
AvastWin32:FakeAV-ESP [Trj]
Ad-AwareGen:Variant.Cerbu.82817
SophosGeneric ML PUA (PUA)
ComodoTrojWare.Win32.Injector.AQJ@4zto9a
DrWebWin32.HLLW.Siggen.4811
ZillyaTrojan.AntiAV.Win32.5678
McAfee-GW-EditionW32/Worm-FNH!EE01C35F2A80
SentinelOneStatic AI – Suspicious PE
EmsisoftGen:Variant.Cerbu.82817 (B)
APEXMalicious
GDataGen:Variant.Cerbu.82817
JiangminTrojan/Onescan.ma
WebrootW32.Trojan.Gen
AviraTR/Dropper.Gen
ZoneAlarmHEUR:Trojan.Win32.Generic
MicrosoftTrojan:Win32/Wacatac.B!ml
CynetMalicious (score: 100)
AhnLab-V3Trojan/Win32.Agent.R72946
VBA32Worm.VB.Autorun.gen
ALYacGen:Variant.Cerbu.82817
MAXmalware (ai score=89)
CylanceUnsafe
RisingTrojan.Generic@AI.93 (RDML:uITn6m89mcRqVKTzpZwymg)
YandexWorm.Agent!8zYvCQOZNvQ
IkarusWorm.Win32.Esfury
FortinetW32/Generic.AC.753!tr
AVGWin32:FakeAV-ESP [Trj]
CrowdStrikewin/malicious_confidence_100% (D)

How to remove Worm.Esfury.A?

Worm.Esfury.A removal tool
  • Download and install GridinSoft Anti-Malware.
  • Open GridinSoft Anti-Malware and perform a “Standard scan“.
  • Move to quarantine” all items.
  • Open “Tools” tab – Press “Reset Browser Settings“.
  • Select proper browser and options – Click “Reset”.
  • Restart your computer.

About the author

Paul Valéry

I'm a cyber security analyst and data science expert with 5+ years of experience with security software contractors.

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