Malicious RTF — malware analysis report

Static analysis result for SHA-256 3dcdd3a14608c289…

MALICIOUS

RTF

1.42 MB Authoring application: Msftedit 5.41.15.1507
MD5: 7b6d9e9a233cea083489f42ea21a075c SHA-1: cdf192d7aefbecf2732e86e07b285eaf543219b3 SHA-256: 3dcdd3a14608c289b65a02365e78fbb2656a71ad79d2adb0c0aa2154436ae313
300 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF file contains a large amount of hex-encoded data within an OLE object, which includes a PE header. ClamAV signatures indicate this is Win.Trojan.Darkkomet-9857871-0. The presence of the PE header within the OLE object strongly suggests the file is designed to drop and execute a malicious payload.

Heuristics 7

  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
  • ClamAV: Win.Trojan.Darkkomet-9857871-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Darkkomet-9857871-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Package object class high RTF_OBJCLASS_PACKAGE
    OLE Package object — can wrap arbitrary files
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1481KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000124.bin
47dfd5e50f513fbaca09ed1afd15bfe5bcc41b3c663cd4a87eb695590dfca46a
rtf-objdata-decoded RTF \objdata at offset 0x124 722211 bytes
Detection
ClamAV: Win.Trojan.Darkkomet-9857871-0
Obfuscation or payload: unlikely