Malicious PDF — malware analysis report

Static analysis result for SHA-256 e71931318ee02faf…

MALICIOUS

PDF

83.6 KB Created: 2021-09-04 12:47:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2a8580b67d8aa22422bb6f5c8c926163 SHA-1: cfba89d89ded8815e9fb6601d1cea108e1e3ca2c SHA-256: e71931318ee02faf0cbb6d29ed2738e1206f7bab134c7723d35b51f35bb0614b
96 Risk Score

Malware Insights

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

This PDF file contains a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm designed to redirect users. The primary purpose appears to be SEO manipulation or directing users to potentially malicious content hosted on these compromised domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://martas.vodrsport.cz/uploads/files/silavufoxuvifogu.pdf In PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/a78e598f45074b304b5546fe1f55e89f/romezuxiwozuzinakesoxuk.pdfIn PDF document text
    • http://rothemtour.com/FileData/ckfinder/files/20210714_F766345BBEA205A3.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160cd3f038d3d3---66515495833.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd9ba96d525---24173177860.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160ddf5fbb0a7d---61822449901.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/wakutemorom.pdfIn PDF document text
    • https://tasivn.com/upload/ck/files/78525715423.pdfIn PDF document text
    • http://www.grupoaccs.net/ckfinder/userfiles/files/41254207172.pdfIn PDF document text
    • http://dh-life.com/ckfinder/userfiles/files/rokalu.pdfIn PDF document text
    • http://hanlacsclub.com/ckupload/files/81761608716.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/wowotagolize.pdfIn PDF document text
    • http://blessedfamilycovenant.org/clients/c/cb/cb727bc273eb4203dc66fb73741ae5ae/File/galebizirekorawozaber.pdfIn PDF document text
    • http://ychnjl.net/userfiles/files/bakigofilud.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607f87c92670c---kuwetalivoketoxixere.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/5232256587.pdfIn PDF document text
    • https://digireg.it/upload/dowifopudifusazijal.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/7vntcg8ski6jpippdp1qnfe15e/wixarutajukekinixijopali.pdfIn PDF document text
    • http://architects-desk.com/uploadsfile/nuvukagon.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc00f781529---95589237052.pdfIn PDF document text
    • https://udruga-invalida.hr/files/7086466299.pdfIn PDF document text
    • http://prestopc.it/upload/file/34632520232.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/5806651903.pdfIn PDF document text
    • http://www.serge-valentin.net/ckfinder/userfiles/files/rikapokadifiriwu.pdfIn PDF document text
    • https://vibanghanoi.com/uploads/files/popedusezapukuraxixa.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/47558089006.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=knee+joint+examination+pdfPDF 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_off0000e218.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE218 17800 bytes
SHA-256: 4686b38b335fcd62f79a5a122c9240b33feb1c77595a9d02928b5102ceecd371
font_01_sfnt_off0001107c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1107C 10568 bytes
SHA-256: 6c4103fac9e4d20ea72fa6eee2fd09467df22e3a24d143ffc2fb974284e18216
font_02_sfnt_off00012891.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12891 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1