Malicious RTF — malware analysis report

Static analysis result for SHA-256 eb7535c6f14d0b05…

MALICIOUS

RTF

63.5 KB First seen: 2019-05-31
MD5: 7d23d97c8747851ccca1267fedfac3f5 SHA-1: 61fd0ae7554691c2ce5985efedff7541bae4bfbc SHA-256: eb7535c6f14d0b05fbea558b6bd2eed0d40a9f32fd00c7a08d6cbd547da49035
240 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains embedded OLE object data, specifically triggering critical heuristics for RTF_EQUATION_EDITOR and CVE_2017_11882. This indicates the file is designed to exploit a vulnerability in the Equation Editor component of Microsoft Office. The exploit likely leads to arbitrary code execution on the victim's machine, commonly delivered via spearphishing attachments.

Heuristics 6

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • Heap-spray pattern detected high SC_HEAP_SPRAY
    Repeated 0x07 bytes found
    Disassembly
    Attempted x86 opcode disassembly
    0000002B  07                pop es
    0000002C  07                pop es
    0000002D  07                pop es
    0000002E  07                pop es
    0000002F  07                pop es
    00000030  07                pop es
    00000031  07                pop es
    00000032  07                pop es
    00000033  07                pop es
    00000034  07                pop es
    00000035  07                pop es
    00000036  07                pop es
    00000037  07                pop es
    00000038  07                pop es
    00000039  07                pop es
    0000003A  07                pop es
    0000003B  07                pop es
    0000003C  07                pop es
    0000003D  07                pop es
    0000003E  07                pop es
    0000003F  07                pop es
    00000040  07                pop es
    00000041  07                pop es
    00000042  07                pop es
    00000043  07                pop es
    00000044  07                pop es
    00000045  07                pop es
    00000046  07                pop es
    00000047  07                pop es
    00000048  07                pop es
    00000049  07                pop es
    0000004A  07                pop es
    0000004B  07                pop es
    0000004C  07                pop es
    0000004D  07                pop es
    0000004E  07                pop es
    0000004F  07                pop es
    00000050  07                pop es
    00000051  07                pop es
    00000052  07                pop es
    00000053  07                pop es
    00000054  07                pop es
    00000055  07                pop es
    00000056  07                pop es
    00000057  07                pop es
    00000058  07                pop es
    00000059  07                pop es
    0000005A  07                pop es
    0000005B  07                pop es
    0000005C  07                pop es
    0000005D  07                pop es
    0000005E  07                pop es
    0000005F  07                pop es
    00000060  07                pop es
    00000061  07                pop es
    00000062  07                pop es
    00000063  07                pop es
    00000064  07                pop es
    00000065  07                pop es
    00000066  07                pop es
    00000067  07                pop es
    00000068  07                pop es
    00000069  07                pop es
    0000006A  07                pop es
    0000006B  07                pop es
    0000006C  07                pop es
    0000006D  07                pop es
    0000006E  07                pop es
    0000006F  07                pop es
    00000070  07                pop es
    00000071  07                pop es
    00000072  07                pop es
    00000073  07                pop es
    00000074  07                pop es
    00000075  07                pop es
    00000076  07                pop es
    00000077  07                pop es
    00000078  07                pop es
    00000079  07                pop es
    0000007A  07                pop es
    0000007B  07                pop es
    0000007C  07                pop es
    0000007D  07                pop es
    0000007E  07                pop es
    0000007F  07                pop es
    00000080  07                pop es
    00000081  07                pop es
    00000082  07                pop es
    00000083  07                pop es
    00000084  07                pop es
    00000085  07                pop es
    00000086  07                pop es
    00000087  07                pop es
    00000088  07                pop es
    00000089  07                pop es
    0000008A  07                pop es
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • 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_off0000db5d.bin rtf-objdata-decoded RTF \objdata at offset 0xDB5D 4190 bytes
SHA-256: 156a78fb400427074a37345aaf8fa2eb5f1c541420f5e242801458652a6e22e4