Malicious PDF — malware analysis report

Static analysis result for SHA-256 d87738ceeacc70c3…

MALICIOUS

PDF

72.1 KB Created: 2021-09-24 23:34:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b290e07d40faf183b8142e3c8f32511b SHA-1: d10d4daa012ef9eacab21ef70889d3adfb4b93eb SHA-256: d87738ceeacc70c32e430a5f3d6fea0114fa39bfceb4f25c2d6453813b98e27b
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable domains and are structured as a link farm. The ML classifier strongly indicates maliciousness. The presence of embedded JavaScript suggests an attempt to execute code, likely to download or redirect to a second-stage payload from one of the listed URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://vp-dmsh.ru/admin/ckfinder/userfiles/files/zipisabesuk.pdf In PDF document text
    • http://baove247.org/upload/files/sitew.pdfIn PDF document text
    • https://huangs.tw/uploads/files/202109131611454186.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210909_050109.pdfIn PDF document text
    • http://huseyindurmuslar.com/images_upload/files/pisekopomi.pdfIn PDF document text
    • http://szkolka-wiercioch.pl/files/file/vogero.pdfIn PDF document text
    • http://elskenecologie.nl/files/wibegokenadefajomugig.pdfIn PDF document text
    • https://cordovajewelry.com/images/file/bovekile.pdfIn PDF document text
    • https://nulifeus.com/~nulife/userfiles/file/pegegawerokopewerijunof.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/kolopebidowe.pdfIn PDF document text
    • http://mayersoffice.com/userfiles/file/fibexajuditakebufigerovow.pdfIn PDF document text
    • http://www.cemeba.com/uploads/ckfinder/files/mazutivimagowadogu.pdfIn PDF document text
    • https://mallenmediations.com/mallenmediations/images/userfiles/file/wubisadetusu.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/6652200309.pdfIn PDF document text
    • http://mrpokedb.com/uploads/files/jojajewerenumuxelok.pdfIn PDF document text
    • http://colorfulmedia.de/fotki/fotki/file/mexefazusojapuxekewo.pdfIn PDF document text
    • https://greenfuturevietnam.com/Upload/files/54018611482.pdfIn PDF document text
    • https://12waktu.com/contents/files/18395166458.pdfIn PDF document text
    • http://clanlogging.com/userfiles/file/29636392087.pdfIn PDF document text
    • http://haenuri.net/ckupload/files/76228553291.pdfIn PDF document text
    • https://truonggiangcompany.com/userfiles/file/luledukiwi.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/50112420201.pdfIn PDF document text
    • http://fge-service.com/userfiles/file/27054635131.pdfIn PDF document text
    • http://tomei4x4.jp/js/upload/files/sezizoj.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/925eed59adf9271fb5004ca2853b3189/jugewamonob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=android+studio+take+photoPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b62c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB62C 10616 bytes
SHA-256: 1e23ed07cc13c20391d5438fd23a82263d7cb662f22da090bc661b8eefb1504b
font_01_sfnt_off0000ce6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE6C 17096 bytes
SHA-256: 2ad003c89d619e9916d9fbdaa66750cf62d3f8ab997f97bcf7946d14144c5cea
font_02_sfnt_off0000fa66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1