Malicious PDF — malware analysis report

Static analysis result for SHA-256 43def5c6fba6c748…

MALICIOUS

PDF

97.9 KB Created: 2021-08-30 20:07:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e18c768bc987eb786f3c8f4235f9190f SHA-1: c2176b80873145d0f49ff7091d58018dd3224b8e SHA-256: 43def5c6fba6c748f65e7c9fba397e183901b63c3cc87fd209fdc5b9d9d4d3e0
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs and link farms pointing to various websites, many of which appear to be compromised WordPress installations or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests the document's primary purpose is to redirect users to external sites, potentially for SEO manipulation or to serve further malicious content. No scripts were extracted, but the PDF structure itself is indicative of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://oniceh.ru/uplcv?utm_term=abstraction+in+research PDF link annotation
    • http://architettoseneca.com/userfiles/files/24787163144.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/ecad6ccfa3b0ed95004b8023bcd29f0c/sobolisimonex.pdfIn PDF document text
    • http://rm-centr.ru/uploads/file/87604633238.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/5mnijqjkctbkodgmts1b50r5us/mizikebulabeke.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/3621554746.pdfIn PDF document text
    • https://fzclicks.com/demo/files/editor/file/63206546044.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1607cbd8ee886d---bowefexabuso.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/s2b5vqp53dn68p8fpnh08vs1ct/27045171436.pdfIn PDF document text
    • http://yuemeism.com/uploadfiles/files/kemuwipowirigudozeto.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a086c7dbf9e---minanut.pdfIn PDF document text
    • https://chiuman-hk.com/images/file/sezaf.pdfIn PDF document text
    • http://locnuocvietmy.com/Images_upload/files/wurawozosodefitofomarofem.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/d366119c4194028eb9a33bda60f6582b/20431635055.pdfIn PDF document text
    • https://memoservicesrl.it/file/paburibap.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16124ff632bf0e---89065844613.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210630114425.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/vopomutoniragerijone.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/95352786219.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/piwura.pdfIn PDF document text
    • http://candemdientu.com/Images_upload/files/lodinevebuwowasileza.pdfIn PDF document text
    • http://wearefamilypalestine.com/clients/3/3b/3bc38fc23f9ffb54b20226cbd6ad6ce3/File/zenakuridejewibon.pdfIn PDF document text
    • http://dentistturkey.com/image/files/jofopota.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/777745163.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1b3a5a29f8---98773801510.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/160756d95ddc93---tolevawof.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_off00011948.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11948 18340 bytes
SHA-256: d00b2b79b15a712e681d84a0702a513e0925a0ff4effa53e0cf3a0ee4b097ce8
font_01_sfnt_off000148d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000160ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x160EF 10404 bytes
SHA-256: 428cd7da7d9f96e7bc2d1271628d9627cf48fdcc3725d8901c46cb723538fb3a