Malicious PDF — malware analysis report

Static analysis result for SHA-256 2620d3cf4d0d38b7…

MALICIOUS

PDF

83.1 KB Created: 2021-09-07 06:59:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 903e78b89c6a496296dc67829d708a4a SHA-1: 2ecfb26ec7762c3a02bcd2bbea9cc787ac621864 SHA-256: 2620d3cf4d0d38b7e6e11758f48f102e60d57cd24717cab02f8419fe59202637
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier strongly indicates maliciousness, supported by numerous heuristics identifying the PDF as a link farm hosted on compromised WordPress sites and disposable domains. The embedded URLs likely lead to further malicious content or phishing pages. No scripts were extracted, but the overall structure and URL patterns are consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://krisoc.ru/uplcv?utm_term=eken+doorbell+manual PDF link annotation
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c56497e92b2---84252466175.pdfIn PDF document text
    • https://a1-recruitment.fr/v2011/Files/fck_upload/file/jubovofer.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f49d9cd09e---ganov.pdfIn PDF document text
    • http://sattosushi.com/uploads/files/fiwivivurepajisiripo.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/mivune.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/704815cc7525ff3a9014015a2c2ce645/dejevetafulinepamixin.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/67aa49ba224a18a56ae52d1948ca368d/70656544635.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b1d43de04e1---novetaxuperinulavel.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/86451192196.pdfIn PDF document text
    • http://romangruszecki.com/uploaded/file/42348922744.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/jutitotoso.pdfIn PDF document text
    • http://educationexplosion.com/clients/a/aa/aae59ec6301d25964842a0067e0ae100/File/91011626321.pdfIn PDF document text
    • https://easresidence.ro/app/webroot/files/userfiles/files/zixewiburivuteg.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612d871f08661---meguwemowubedutuvex.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/xikudifopug.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f08d05dfea---zibuguvabuburufizuv.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16072d67c570f8---80241299843.pdfIn PDF document text
    • http://jumpstart.mobi/ckfinder/userfiles/files/49741359012.pdfIn PDF document text
    • https://kristinanamaste.eu/files/33397490306.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb72e337988---57219954513.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/parikukekomuzumil.pdfIn PDF document text
    • http://1hozain.ru/files/userfiles/files/71384936031.pdfIn PDF document text
    • https://thinkhigh-tech.com/d/files/tanewefuwerupago.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_off0000e164.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE164 17956 bytes
SHA-256: 6881f884999ea2414426e35507fd7cf1b78a204292752459dd91ba183e5ee147
font_01_sfnt_off00010f7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012791.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12791 10368 bytes
SHA-256: 4de21d7043680b96b16c6533b213fd9fb919dbe228fd2f62610d3eb255f36d24