Malicious PDF — malware analysis report

Static analysis result for SHA-256 6504b5e306384fc8…

MALICIOUS

PDF

82.5 KB Created: 2021-09-13 22:05:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4f28a4d2e85d0c99b097922d103a2cfc SHA-1: 17526b0e606346a6b4af07a850674dbb328a91d8 SHA-256: 6504b5e306384fc8a6180f3d414c1b07704101e5bde6540c74382e22299e2255
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm it's a link farm designed to lead users to potentially harmful content. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://queure.ru/uplcv?utm_term=can+i+get+paramount+on+firestick PDF link annotation
    • http://stomerijindex.nl/images/uploads/bakezezemavu.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0b753c784---zuwezobisok.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613caa17cc6a7---87758151375.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/tuwudobof.pdfIn PDF document text
    • http://forti.in/userfiles/file/ranakofonuso.pdfIn PDF document text
    • http://ilturismoinitalia.it/userfiles/files/92575918439.pdfIn PDF document text
    • http://kukdae.com/files/fckeditor/file/29765060522.pdfIn PDF document text
    • http://gurukripapublicschool.com/userfiles/file/ligapasij.pdfIn PDF document text
    • https://polandpools.com/contents/files/norabasivisirovudadir.pdfIn PDF document text
    • http://svazekobciorlice.cz/userfiles/file/rimokewezir.pdfIn PDF document text
    • http://customize.fr/fckeditor/editor/filemanager/connectors/php/img/Editor/file/41029935194.pdfIn PDF document text
    • https://777mto.info/contents/files/95966193021.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c974dfc86---kurotorojujipubasebifi.pdfIn PDF document text
    • http://nensi.si/upload/file/15566201921.pdfIn PDF document text
    • http://pomodorolennep.de/gfx/userfiles/files/jorabewududikanafip.pdfIn PDF document text
    • http://neoneofitou.com/ckfinder/userfiles/files/26343034991.pdfIn PDF document text
    • https://petala.gr/userfiles/file/82427429554.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/ruxaxo.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1dfdedd9d---49496429692.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/67939944135.pdfIn PDF document text
    • https://drlanda.hu/user/file/tawogulaselez.pdfIn PDF document text
    • https://laptoptranganh.com/data/dulieu/files/jusabusepesoxujevita.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_off0000daa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA8 18248 bytes
SHA-256: eeb2848f5cce8dbd59ef4dab45846dd2fb813f592484976b1cd9690d227d5916
font_01_sfnt_off00010a9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A9B 11000 bytes
SHA-256: 604ceada43748630e412bd23b7be007669659041ff397f9b7d4248e04ff57b85
font_02_sfnt_off00012442.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12442 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1