Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d74c1228dfbc8bb…

MALICIOUS

PDF

72.9 KB Created: 2021-09-07 22:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3ed05eb3b7625aabc7a10d83e3b36f7b SHA-1: 5bf6261c0f85e20d2116ec67cdadb7d6093293f0 SHA-256: 4d74c1228dfbc8bb1a1e5da4ce35e0a672fa8c29c28ceafeb21cdc000ee5df50
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 other PDF files hosted on various websites, many of which appear to be compromised. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this is a link farm, likely used for SEO manipulation or to distribute further malicious content. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/ab921702ac72dc8ad7b2cb819e77ef4f/jafukazaluwijetizaxalizi.pdf In PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/9qm35e6qc9bdapsliifd8k5edg/nomosorun.pdfIn PDF document text
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/99289483976.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a821ded99d2---sokipamukabesarawo.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/qfal14jsiiv57mafp05kqfuokq/ralumare.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/tidebutewofasozew.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a363622b924---89883759064.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/welow.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/vifopagunedolipasasiba.pdfIn PDF document text
    • http://blossomtour.net/FileData/ckfinder/files/20210808_321A37D30C188106.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/xuzafizeregifa.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/78hksguhteausj6t52a0hv1kfp/pobarisupawa.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/90033511593.pdfIn PDF document text
    • http://thaisomboonautopart.com/userfiles/files/44614282835.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/2b779637ea062308a9660a7ecb0ed1d4/25583739297.pdfIn PDF document text
    • http://minutemen-jrotc.com/clients/84940/File/fawegolepolux.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fa354be34f5---34762557189.pdfIn PDF document text
    • http://maginsaatmetal.com/resimlerfiles/didoruzareseg.pdfIn PDF document text
    • http://hart-metale.pl/gimnazjum/userfiles/file/66075826762.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/160757d661cafb---59333047351.pdfIn PDF document text
    • http://svenskafik.se/uploads/fckeditor/file/92022844768.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce13c4fc4d---xemojajawofagoji.pdfIn PDF document text
    • https://hopadive.cz/ckfinder/userfiles/files/lunatojadupepokumupeku.pdfIn PDF document text
    • https://kueapem.com/contents/files/dasinipadusefutulufobut.pdfIn PDF document text
    • http://phone-server.com/userfiles/file/vikifagirelugifupumube.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=nptel+civil+engineering+pdf+notes+downloadPDF 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_off0000bafd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d30f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD30F 16280 bytes
SHA-256: cac0e49c3429935b8f620dda01c2a76d4a77ddc7383a7208c587a19a6d9ce963
font_02_sfnt_off0000fceb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCEB 10924 bytes
SHA-256: aa01c5e5bcd5e5cfd5c77103e8fd135f3aa847c10f58858ecc6a215eb43732fd