Malicious PDF — malware analysis report

Static analysis result for SHA-256 855a3d9dbbb7ef89…

MALICIOUS

PDF

82.5 KB Created: 2021-10-10 19:30:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a78cae9900cb2422cfd2b42dafe3b87c SHA-1: 6345af858ebf9d23993c2b7e05752052d5e05484 SHA-256: 855a3d9dbbb7ef896776ca6248ee44b8acb19ecb3e78963ffc7e94185b306a15
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is the primary mechanism for executing malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://ux02.wadhost.com/js/ckfinder/userfiles/files/73349918480.pdf In PDF document text
    • http://botosani.ro/img/uploads/file/gefokore.pdfIn PDF document text
    • https://oancora.com/ckfinder/files/84634535307.pdfIn PDF document text
    • http://evolution-dev.com/file_media/file_image/file/koxebeninajaliwovimape.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/59694482176.pdfIn PDF document text
    • https://full-flavors.com/img/Data/file/84113908743.pdfIn PDF document text
    • http://spodne-pradlo-2bpoint.sk/UserFiles/File/tatorewenadefomonifafuwox.pdfIn PDF document text
    • http://tareeapartment.com/user_img/files/karuzixi.pdfIn PDF document text
    • http://yesfabric.com/images/upload/File/38119219942.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/77734456423.pdfIn PDF document text
    • https://binarbaid.com/public_html/userfiles/file/90261631018.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/wanazelapigekaxirexiwise.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/50267213382.pdfIn PDF document text
    • http://yjsyrj.com/userfiles/file/nugevilavebogidilirebo.pdfIn PDF document text
    • http://aajude.pt/backoffice/ckfinder/userfiles/files/zovafuno.pdfIn PDF document text
    • http://papaicountrylodge-longstay.com/user_img/files/78923674014.pdfIn PDF document text
    • http://bukharasuwanee.com/sites/default/files/file/kanimidogi.pdfIn PDF document text
    • http://tridiart.cl/ckfinder/userfiles/files/14306328850.pdfIn PDF document text
    • https://amoslodge10.org/ckfinder/userfiles/files/majotamusebavanu.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210925191934804.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/133948513.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/sivizoji.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/dafeza.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1612fce4bce1ed---jomexegaruvumuk.pdfIn PDF document text
    • http://ptktent.ru/userfiles/file/fatonuwobofesotojera.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=ielts+book+11+test+4+reading+answersPDF 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_off0000db4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB4A 10820 bytes
SHA-256: e0c30aa1c488ec7cbf811d9b97f84a5ad740f7a8f8a1cf454b18e3fe173bdec9
font_01_sfnt_off0000f449.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF449 18388 bytes
SHA-256: 9419d65cb152ef26cf4a2f3f27ada7d22ebdedb1983947df086df2145c9e558f
font_02_sfnt_off00012405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12405 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1