Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c8ec37effdf4d03…

MALICIOUS

PDF

76.8 KB Created: 2021-09-13 09:08:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 50ef0564bc342c90701ab53a6929c3c0 SHA-1: 6c3882d5a22e1f31a994600b0b1350cd30a5d2ef SHA-256: 2c8ec37effdf4d0301f041ce2aa0f9bd028596e94b2a3c8fdd4a91348c085a36
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest the document's primary purpose is to redirect users, potentially to sites hosting malware or engaging in phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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.
  • 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://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/10l00e9g4b01ufog8esvn6i44q/3799586639.pdf In PDF document text
    • http://szyoujin.com/UploadFile/file/20210906233056238.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/92522625191.pdfIn PDF document text
    • http://mariautonoleggiomarsala.it/userfiles/files/14302651969.pdfIn PDF document text
    • https://mraos.com/web/userfiles/file/96606227429.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1e2fa1eb9---fasasofabubomumajitezaz.pdfIn PDF document text
    • https://marljivo.hr/userfiles/file/59759167949.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/feziwos.pdfIn PDF document text
    • https://techlan.pl/files/file/lojetijogigobev.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/nerirat.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8dc68b0fe---sunavorob.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/75848117231.pdfIn PDF document text
    • https://wickedcheesy.com/images/file/57811100490.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8ad64dd69---pipodogozededapapulov.pdfIn PDF document text
    • https://mimpishio2.com/contents/files/pinatufebub.pdfIn PDF document text
    • http://baruraprotidin.com/assets/ckfinder/core/connector/php/uploads/files/9265972427.pdfIn PDF document text
    • http://kammed.com/userfiles/file/40365873834.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16130edaea3ef4---93877705011.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/161317f2e6c2f8---95455201954.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/184df62b9b5597e3c9fa91192769d421/nikarevopesekobok.pdfIn PDF document text
    • http://joesservicecenternj.com/userfiles/files/kisanabujiziguboj.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/20890777652.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=live+cricket+match+streaming+online+videoPDF 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_off0000c505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC505 18356 bytes
SHA-256: 9af4afa07120e90a9e7613bf21ec07d749889f95ab85afa2a90db6b405518d19
font_01_sfnt_off0000f4d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D9 10932 bytes
SHA-256: f57568912a11dee062918753a5a778565e6f7015be921da83a1a6fba18918189
font_02_sfnt_off00010dd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1