Malicious PDF — malware analysis report

Static analysis result for SHA-256 db133830385d0a6b…

MALICIOUS

PDF

80.9 KB Created: 2021-09-09 13:06:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b2e381487359de75694daf97fb7040c1 SHA-1: c544dbdf639d93446c000ba6af0a87a5a3b0389f SHA-256: db133830385d0a6b14172eee68e68b48c7d52a963817e08556aa170cf1e09ed0
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs pointing to various PDF files, suggesting a link farm designed to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of multiple disposable domains and a high ML score points to a coordinated phishing effort.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 https://synerhu.ru/uplcv?utm_term=mr+bones+part+1+full+movie+download PDF link annotation
    • https://hostsolutions.ro/app/webroot/files/userfiles/files/87059613335.pdfIn PDF document text
    • http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/32632691630.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/zitafebafebof.pdfIn PDF document text
    • http://cansuyu.org/resimler/files/28846244026.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/73279484938.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161323b79a5550---73157928359.pdfIn PDF document text
    • http://vistobrasil.net/uploads/file/51605708055.pdfIn PDF document text
    • http://caytrong.vn/Images_upload/files/52009646522.pdfIn PDF document text
    • https://mimpishio.com/contents/files/14285529782.pdfIn PDF document text
    • http://hoteldarim.ir/basefile/hoteldarimir/files/29249954451.pdfIn PDF document text
    • http://wonderful-foods.net/userfiles/file/mabiwijolanujapisefobemem.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/70693694777.pdfIn PDF document text
    • https://alpinashop.rudy-ra.com/files/2447631594.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/renoge.pdfIn PDF document text
    • https://deitratech.com/userfiles/file/gaguviv.pdfIn PDF document text
    • http://z500.si/files/43986695707.pdfIn PDF document text
    • http://saraya-shop.ru/upload/files/4423211020.pdfIn PDF document text
    • http://zdrowejaja.com/Upload/file/30616559958.pdfIn PDF document text
    • https://www.truckersplantparts.co.uk/ckfinder/userfiles/files/xeguginunenutojubifezu.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/burerutokezopatufujuk.pdfIn PDF document text
    • https://gotoko.com/cmsv2/upload/files/81643138037.pdfIn PDF document text
    • http://bjsddesign.com/filespath/files/20210906024848.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/menozevobusujifojapumi.pdfIn PDF document text
    • http://apisicul.com/userfiles/files/92417918369.pdfIn PDF document text
    • 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_off0000d70b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD70B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF22 11096 bytes
SHA-256: 19495a9a5069a1ef5419eb23e69c993db37c9c0a872b02ff842cd4b39d5c4a61
font_02_sfnt_off000108e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E4 17552 bytes
SHA-256: d254604f9534ee70ab3955dbf65284999d023418379d318061a7491563f44e99