Malicious PDF — malware analysis report

Static analysis result for SHA-256 c835b6bb6dcf2bec…

MALICIOUS

PDF

76.9 KB Created: 2021-05-02 11:02:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 77e88f61867f4b54d87960fb5aa552db SHA-1: 058cdc96cca80b4d5bd4642242b1d7660822d33f SHA-256: c835b6bb6dcf2becdeb29a3fafea5d13d46444b68a6f8d8af4d8eddcee0fd265
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of external links, identified by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, suggesting it's part of a link farm designed to drive traffic to various websites. The embedded URLs, such as 'https://botokaw.ru/strik?utm_term=is+there+any+prep+needed+for+an+echocardiogram', and the numerous other linked PDFs indicate a malicious intent to redirect users. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://botokaw.ru/strik?utm_term=is+there+any+prep+needed+for+an+echocardiogram PDF link annotation
    • https://pidofuvu.weebly.com/uploads/1/3/0/7/130739764/zibumonujob.pdfIn PDF document text
    • http://ribininewo.22web.org/wisoximorurelufus.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502906/normal_6030307f78f0a.pdfIn PDF document text
    • http://nitupewefo.iblogger.org/halcones_de_venta_libro_descargar_gratis.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383582/normal_601ab0099a63e.pdfIn PDF document text
    • http://texegevesimiruv.22web.org/guvagiri.pdfIn PDF document text
    • https://jexabuwojese.weebly.com/uploads/1/3/1/3/131384148/pulusikeburuto.pdfIn PDF document text
    • http://ziriwurupi.22web.org/how_to_find_the_cylinder_volume.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408711/normal_5fd665402d332.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377109/normal_604ebf74c3097.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470027/normal_605df98bd7a3a.pdfIn PDF document text
    • http://fixebojamofi.iblogger.org/declutter_your_mind_download.pdfIn PDF document text
    • http://organize.shop/jamimunanojibadifudubaj4fjwg.pdfIn PDF document text
    • https://fuzewejobedogu.weebly.com/uploads/1/3/1/4/131482867/mebabivulezuk-futulatupa-torig.pdfIn PDF document text
    • http://mmamba.ru/kizonuxutoxupovutimageko40o9r.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368505/normal_606ea735207df.pdfIn PDF document text
    • http://generatorsale.ru/ios_apprentice_8th_edition_free_downloadvn8ly.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420438/normal_6067de280c8f3.pdfIn PDF document text
    • https://sifavebizibi.weebly.com/uploads/1/3/4/0/134040704/woluvu-wazotuker.pdfIn PDF document text
    • http://vsspb.ru/would_you_prefer_a_nature_metaphorujfsa.pdfIn PDF document text
    • https://kepijifawobi.weebly.com/uploads/1/3/5/3/135388201/cf8a861c79.pdfIn PDF document text
    • http://buloshnaya.site/20081140275n12ax.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gawekavadave.epizy.com/20883218383.pdfIn PDF document text
    • http://lorajazibosiner.epizy.com/kolebusaruxesiv.pdfIn PDF document text
    • http://xoxemofunox.epizy.com/framework7_icons_cheatsheet.pdfIn PDF document text
    • http://lovagijikem.epizy.com/backward_caste_list_in_telangana.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1D 5576 bytes
SHA-256: 94e54ba303780d39d0da68faec2038161db50351db1ac3e110800db521fdb790
font_01_sfnt_off000101fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FD 10556 bytes
SHA-256: 9aaed71cf04ada400af939d8a9e580a1d176282cbeae67e196e98c98e897f59f