Malicious PDF — malware analysis report

Static analysis result for SHA-256 54d3955deff65c49…

MALICIOUS

PDF

71.5 KB Created: 2021-09-26 16:10:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9b5f49804c21ef552340d3c3eaf1227d SHA-1: c4364ab1a80d0ee847e0d73f09b0cfaf10b121bc SHA-256: 54d3955deff65c49589a2791a0a31214f621b4b2b819e49273cf3d299d0c40d7
104 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 compromised CMS uploads or disposable hosting, indicating a link farm for SEO manipulation or malicious redirection. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. The presence of embedded JavaScript suggests potential for further exploitation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://chcial.ru/uplcv?utm_term=english+placement+test+sample+pdf PDF link annotation
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/67483703508.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/161378241e1e41---sizarasudidewan.pdfIn PDF document text
    • http://creativecoms.net/userfiles/file/gifowelivunudizavaxoguxid.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/gudulu.pdfIn PDF document text
    • https://rotterdampools.com/contents/files/kanoseka.pdfIn PDF document text
    • http://eapver.com/upload/ckimg/files/202109251652565155.pdfIn PDF document text
    • https://vocembalo.ch/userfiles/file/tajineboxuwafijavurij.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3b9d28b41---36768711756.pdfIn PDF document text
    • http://viviapalermo.com/userfiles/files/kinukufodanonuzedopujej.pdfIn PDF document text
    • http://ryouhurt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xidarakabuzosos.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210912030038.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/7898287711.pdfIn PDF document text
    • http://dijladentalcenter-qa.com/userfiles/file/66204429345.pdfIn PDF document text
    • http://evergreendentistryva.com/app/webroot/js/ckfinder/userfiles/files/tazawe.pdfIn PDF document text
    • http://consade.com/userfiles/file/78687579604.pdfIn PDF document text
    • http://plafondchauffant.fr/img/user/file/jinikoxiwisevapi.pdfIn PDF document text
    • http://musicpark-live.de/userfiles/file/zoxetozakujuzawonavotek.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/6a8785eeb62e17601a24f550e2964e62/zedanakexi.pdfIn PDF document text
    • http://vecsecity.info/editor_up/68169638376.pdfIn PDF document text
    • https://cytokin.ca/upload/editor/file/57203297487.pdfIn PDF document text
    • http://geomanteia.com/userfiles/files/gepobugaleg.pdfIn PDF document text
    • http://sgo-bage.com/public/files/files/91060866777.pdfIn PDF document text
    • http://boletos.luzservicos.com/ckfinder/userfiles/files/fanogosutowipadivu.pdfIn PDF document text
    • http://nordicwalkingturak.hu/_user/file/67170870874.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_off0000b327.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB327 10828 bytes
SHA-256: fb6abd29ce67fc14c4a8f252a8ba6cf29922e1115d1813631849e39dfda1eb9c
font_01_sfnt_off0000cbb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3C5 17208 bytes
SHA-256: 6b8820eed45fa23ffa30f6334cffcd17a6372bfe47346ff1526ff5309e54317d