Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a8d4a038dfd0c64…

MALICIOUS

PDF

88.2 KB Created: 2021-07-05 02:31:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: b1653b76a54d888e8cece1a658774e27 SHA-1: 6c7ddd10862ab4d707a7f379657edb31db6dd4e3 SHA-256: 1a8d4a038dfd0c6400024ad303e76978407d215d24658e5cf1ba443f268c3d29
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites hosting other PDF files. This suggests a link farm or SEO poisoning attack. The ML classifier strongly flagged this PDF as malicious, indicating a high likelihood of malicious intent. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/ec47e188dad449ddd87944d752a63a61/39081973273.pdf In PDF document text
    • http://janandpoos.com/clients/872640/File/12339838042.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160859082864f9---kazemusukijezip.pdfIn PDF document text
    • https://equinox-e.com/upload/files/dilolukofefik.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a823f1e6e38---2800907415.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/162a0262b96b01f29817547103f550cc/pasevof.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160be660e34a7e---39659331255.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/019b33f5ceb0881e1da85bb44c4475fc/vixupufikaxoxomo.pdfIn PDF document text
    • http://xn--82cac8d3ajrc0gd0bo4a7nf3qg.com/userfiles/files/60179909592.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a23fd4b5516---38406602315.pdfIn PDF document text
    • https://plasy.com/uploads/file/vasotopoxobazulowizi.pdfIn PDF document text
    • http://texmet.pl/userimages/file/30283578343.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160729d74578ea---33480220290.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-7-5/20210705050710100196.pdfIn PDF document text
    • http://dharmapremipariwar.org/userfiles/file/lopolep.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608666fcd3de1---45461337144.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d663b586a---28475892171.pdfIn PDF document text
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/f566409a625651dba082d7974eb0cdad/75337957799.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/22217254679.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/96051239361.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/ropufo.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/cd97273b273c340b8d2f61f188c2d43e/nudapadisozeruvedumagit.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794eb56c88c---bebobujoxozinopojuzinane.pdfIn PDF document text
    • http://watsonwilliamsreunion.com/clients/82103/File/wapofefesijexubosifojo.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8a5cbc6e1---16567594358.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=tom+from+mountain+man+net+worthPDF 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_off0000f2df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010af1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF1 19316 bytes
SHA-256: 155ad76cb9fc19800ae3fa55d307160932fc576c6524d2ef339fa6f9714e0fa8
font_02_sfnt_off00013c39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C39 10412 bytes
SHA-256: 0d40eb05a2f7f7680d19ca12978d672d446bf4c7a816af50025fd446d36d10aa