Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a20f43a6ec1712e…

MALICIOUS

PDF

83.6 KB Created: 2021-09-07 18:44:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9fc7531e5b3ef4dcdc8fbf1343411057 SHA-1: 1539e1016f57eb3e386712ce4552a155176e2b93 SHA-256: 3a20f43a6ec1712ea133d944edbc8eb4c13a648e09cfd174177785a1b6c14fca
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous domains, many of which are hosted on compromised CMS uploads or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to external sites, likely for further exploitation or phishing. No scripts were extracted, but the PDF's nature as a link farm is clear.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 http://bibliotekaludwin.pl/img/upload/files/nowopo.pdf In PDF document text
    • http://yonezawanet.jp/units/24250/zcycom/files/46141615692.pdfIn PDF document text
    • http://manajrgvaaradhi.com/cms-uploads/files/80814222039.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/29075270589.pdfIn PDF document text
    • https://drlanda.hu/user/file/gamugixavidedu.pdfIn PDF document text
    • https://roweryelectra.pl/app/webroot/uploads/file/16209658995244.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c26115db9c9---dujenumenejojuditem.pdfIn PDF document text
    • http://kokomo1986.com/clients/31029/File/vofesabogidis.pdfIn PDF document text
    • http://pololanna.com/user_img/files/kuzuzuzowovukafixakuzibi.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/nikemilixazik.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/pewikuwosulunuxonakatex.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/56162405330.pdfIn PDF document text
    • http://cuadepthanglong.com/images/ckeditor/files/94451509128.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/96067974416.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16071e6239ddb2---rozilejonitixofakifuvev.pdfIn PDF document text
    • http://bdn10.cz/files/file/komazewofewizuguvujusud.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb498b57e5---48761571211.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16135c2f6e9ddd---tofila.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/61590191861.pdfIn PDF document text
    • http://www.malagatour.es/ckfinder/userfiles/files/vikuxipakubokivuresopixo.pdfIn PDF document text
    • http://capital96.com/userfiles/file/81920641707.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=irregular+plural+of+nouns+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_off0000e1f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F8 18420 bytes
SHA-256: c1f0977103271cddf361046d3473a22af0e463597136f9679638876eb86b9bce
font_01_sfnt_off00011185.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11185 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001299c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1299C 10532 bytes
SHA-256: 27bd6b0704a722e2f66ca05b6e0039e3e6518e2162af2f0f9764b666bd0dd29e