Malicious PDF — malware analysis report

Static analysis result for SHA-256 1db81110bdda07ec…

MALICIOUS

PDF

88.9 KB Created: 2011-09-20 10:38:42 +08:00 Authoring application: WPS Office 个人版 (via PDFlib 7.0.3 (C++/Win32))
MD5: 35458535961f767e267487e39641766c SHA-1: 6e7ce468ebaba59337ace239e958a2a0d1129d43 SHA-256: 1db81110bdda07ec6f379ba1bc88cd1201dcaeecdade5503908f683acdf2ab0e
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF exhibits characteristics of a phishing lure, including an image-only document with a click-outward action. Heuristics indicate embedded JavaScript and RichMedia (Flash), suggesting an attempt to execute malicious code. The presence of embedded files and ClamAV detection as 'Pdf.Dropper.Agent-7236430-0' strongly points to a dropper functionality, likely designed to download and execute a second-stage payload. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 10

  • Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • ClamAV: Pdf.Dropper.Agent-7236430-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7236430-0
  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector (matched inside decoded stream)
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 2 image(s), only 2 text block(s), carries a click-outward action, and is only 88 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic (matched inside decoded stream)
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 14

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0001.bin
3000b3469a8bd553f177da3f507a5ea2271a3dee1fd5d5343f41950837af583c
pdf-embedded-file PDF EmbeddedFile object 1 at offset 0x3B36 163 bytes
embedded_file_obj0002.bin
66b82b096ae83103365f40b9b767a5582b0a497e4589e7b9323eac0320c61808
pdf-embedded-file PDF EmbeddedFile object 2 at offset 0x3C27 1670 bytes
embedded_file_obj0003.bin
e763ac63c3d21786709e7f462b463575525d0e344202f42dbb96897a01541e78
pdf-embedded-file PDF EmbeddedFile object 3 at offset 0x3F43 785 bytes
embedded_file_obj0004.bin
720c47f19e6a058099295d18a16b7149cc73fe497eb78821ea810f3192228dc4
pdf-embedded-file PDF EmbeddedFile object 4 at offset 0x4138 150 bytes
embedded_file_obj0005.bin
c8a82f67dfd8d68c2f8fe494ca2deee4604701c8f02863bf87d222b992e45de9
pdf-embedded-file PDF EmbeddedFile object 5 at offset 0x4209 2955 bytes
embedded_file_obj0006.bin
4cb349134bdb5f1a1c03281df9b53128ebe947f235398a912a4f0a9f638b24d5
pdf-embedded-file PDF EmbeddedFile object 6 at offset 0x4583 200 bytes
embedded_file_obj0007.bin
4273cd319df227c91b92e5509527bb4f6e1abfb3aa2beec2fb2adb93a8671f62
pdf-embedded-file PDF EmbeddedFile object 7 at offset 0x4676 835 bytes
embedded_file_obj0008.bin
4a60a9864cdf7382475d51051a03fdc43b32c31eb508893ccfccece34957f9f1
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0x484D 56 bytes
stream_002_off000003ed.js
529357503ec67b623d2a12816cdeea62bd639f2b4ff4e568b01c96cc3f5bfc6f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3ED 1363 bytes
stream_003_off000005ca.js
e985b5df65c8c3cf732a9074b575fbc594c1c7f0bccc0994182ec7e5c0f7308a
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5CA 902 bytes
objstm_0047_00.bin
856830b101f28eaa61f2ccb44204fecaa2d0a9658055009fda363a9d3056ff76
pdf-objstm-decoded PDF /ObjStm 47 0 obj (inflated) 2543 bytes
font_00_sfnt_off0000fa8f.bin
9deb1b9f8d540749c7f959968d185dc976dc5754180de3407fbd6b0343327cc1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA8F 25632 bytes
polyglot_child_pdf_off0000f487.pdf
cd0b5823a33a3afb5eb194764e198fd4ac2d38711e197c61a2dce22d8da37d51
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0xF487 28411 bytes
polyglot_child_pdf_off00014b93.pdf
9a95102ad6b4d58a9a742832f61490a27e9b62855fe295b13214addfda321ad3
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x14B93 6127 bytes