Malicious PDF — malware analysis report

Static analysis result for SHA-256 a77d51d31f5853b7…

MALICIOUS

PDF

74.7 KB Created: 2021-09-20 07:31:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 94b3340dbc2e8b2b70446a4e31eeacec SHA-1: ca08c7280ceef85fe4a89dee3d0e8a0264a2287c SHA-256: a77d51d31f5853b7d5d7229a6db57eb2674570360dce1692086c004fb7f98257
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to manipulate search engine results or direct users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://johnmarzillier.com/ckfinder/userfiles/files/54243706073.pdf In PDF document text
    • http://kondicionery-elektrostal.ru/upload_picture/file/45136417323.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/96934538270.pdfIn PDF document text
    • https://nulifeus.com/~nulife/userfiles/file/58634740453.pdfIn PDF document text
    • https://nmg.lv/img/uploads/files/25328702782.pdfIn PDF document text
    • https://cfi-registration.org/buzzboxgift/img/userfiles/files/durikirotinotigadub.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161459c6fe7fe3---48896604611.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/1b19536900b3d14a5d398f732bf13a10/3583296440.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/48426559862.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210903_CE4E35F36EDF59BB.pdfIn PDF document text
    • http://leylatoprak.com/userfiles/file/vofutegekikiwojobofezor.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/95836436174.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/tipesogujufup.pdfIn PDF document text
    • http://bckbytow.naszbip.pl/img/upload/files/xojibotuwutuxeri.pdfIn PDF document text
    • http://f1-rennsimulatoren.de/userfiles/file/tidiximonawevuzeke.pdfIn PDF document text
    • http://paradisetnl.com/FileData/ckfinder/files/20210906_05EFF1E8962D3EB5.pdfIn PDF document text
    • http://traslochimontalto.it/userfiles/files/8702160574.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/e1cfdb7422f7dfda079251b3419ca9d3/xopojeredatitazix.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/27571676965.pdfIn PDF document text
    • https://zzhqhi.com/d/files/30306017837.pdfIn PDF document text
    • http://grandioso.asia/editor_upload_image/file/dobexegudotedu.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/buziranojizapel.pdfIn PDF document text
    • http://mwcapital.net/ckfinder/userfiles/files/luvivitadasaxirojif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=skechers+roblox+id+codePDF 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_off0000bf76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF76 10512 bytes
SHA-256: 675309a919bb820e825bacd62aa86aae834054acce046387a23a651fe87940ed
font_01_sfnt_off0000d775.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD775 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF87 17420 bytes
SHA-256: 611e9b9e1b9227b785cf6ba4ff45a439eb1dfc4a4cef83504478cda4013c1fd4