Malicious PDF — malware analysis report

Static analysis result for SHA-256 a91375e20f9b38e2…

MALICIOUS

PDF

72.5 KB Created: 2021-05-09 15:25:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 60ebd8c33468057cd4be40c8a2ae1e1c SHA-1: ffac23c68681a3521249238322c263c86a338c09 SHA-256: a91375e20f9b38e29c90c4223c9e7f53ad1b1c0b1684f3469dd9201d99db35e5
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of external URIs pointing to compromised WordPress upload directories and other disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users to potentially malicious content. No scripts were extracted, but the numerous links are the primary threat vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://crysiq.ru/uplcv?utm_term=acp+guidelines+for+diabetes+2019 PDF link annotation
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/371407d8acd802d3093b2fabba70264b/kubagorurozovexawunojer.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606dd4240f1ec---87562257288.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094c27e4bbea---75886059050.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606efff3dec80---81604887024.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/soi8n8f8nn9bq5s8fjp8vpa6me/71861353584.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16093f69c2ac03---4664860029.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/8d9c2867cf28cc8aa62acf94bbaaa162/14724895060.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/57904501722.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/55aa4c5db34c9322ca3fd0b8dee5bee4/41114235117.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/tanivaboriv.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/b2f0b60f6685a9f7066cb5cf222395f1/11450355398.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/a1sbsf3v64k5ggr27a77k6o7t9/lavuz.pdfIn PDF document text
    • http://ats-dz.com/userfiles/file/58627330936.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/16078aff830348---sigijixugapagopifozuzasew.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/73878de42ee96d94e88004fef57b2541/vuwubekitoputusanefejoga.pdfIn PDF document text
    • https://heider.ru/wp-content/plugins/super-forms/uploads/php/files/b02e2bb0fc049226def6b0e43e465aa8/kusuruv.pdfIn PDF document text
    • https://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/27ea25e2aac9a6f3e489d63c08a43f29/6769263512.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160751c478f279---jibaridekipubetosojasuvej.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/kltfj5fv19me9j44qocupk3qth/bilusufexuka.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dcaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCAA 5936 bytes
SHA-256: d7efb198e3f598ad17f3962c80c2a327a84945334f366ff010c69870b1bc7993
font_01_sfnt_off0000f0ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EE 10616 bytes
SHA-256: df2504215d23d26185b7147c0e338cfb61f0837c522abdf18b4bbbcb85e7bbe3