Malicious PDF — malware analysis report

Static analysis result for SHA-256 442adad0bff108c0…

MALICIOUS

PDF

83.5 KB Created: 2021-09-24 01:37:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f94a817ba2c7d3601a72694fb16077e9 SHA-1: 4b848f040afc94d1788128aead41c6186e92cf89 SHA-256: 442adad0bff108c0f32d9814e59f9e89224e57bbca477075e77ec002fcfdc5e2
96 Risk Score

Malware Insights

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

The PDF contains numerous links to other PDF files hosted on compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. The primary attack pattern involves luring users to download further payloads or visit malicious sites via these embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://synerhu.ru/uplcv?utm_term=android+push+notification+text+limit PDF link annotation
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16135a5ccbb58d---kimemolaj.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/16136aa6bf0cd2---12873198925.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1b3472c19---91879571886.pdfIn PDF document text
    • http://chemsdano.com/upload/files/bugufewanopolunotabisag.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/c678d3333357b755c3eab53166ea9006/dedumifebijusubefapugowem.pdfIn PDF document text
    • http://desushibar.com/userfiles/file/4974136254.pdfIn PDF document text
    • http://sccsfz.org/upload/2021-09/98837740634.pdfIn PDF document text
    • http://dae-young.kr/upload/fckeditor/file/wukanufapitaveji.pdfIn PDF document text
    • http://szyqjsj.com/UploadFile/file/20210919023405525.pdfIn PDF document text
    • https://ikomsolutions.com/admin/userfiles/file/tubuzajikonafasupefura.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/sumuponibetanuxasikarunim.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/momoli.pdfIn PDF document text
    • http://globalsocialwlefaresummit.com/app/webroot/uploads/ckuploads/files/45884866065.pdfIn PDF document text
    • https://blokhol.com/upload/files/fukafafoxaxijiku.pdfIn PDF document text
    • https://kopari.hu/files/file/43095879237.pdfIn PDF document text
    • http://gurolmumcu.com/userfiles/file/dulomi.pdfIn PDF document text
    • http://umbabox.com/userfiles/file/10477178803.pdfIn PDF document text
    • https://didaktika.drmix.cz/uploads/files/gikeligejuwosakukawu.pdfIn PDF document text
    • https://lecourbe.dk/userfiles/file/66032570676.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/69683138081.pdfIn PDF document text
    • http://getem.pl/files/file/mipalosusi.pdfIn PDF document text
    • http://shiraz.sk/ckfinder/userfiles/files/ninakixel.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/wosuta.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/suwojipedisufumujejisu.pdfIn PDF document text
    • http://fillaracingacademy.cz/ckfinder/userfiles/files/21540003532.pdfIn PDF document text
    • https://ritascreation.com/userfiles/file/67358688854.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_off0000df77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF77 18172 bytes
SHA-256: 3c6c2c15e1127855d6f51f95c8db3e5e9470459cf87799bc804061c3ac3fe760
font_01_sfnt_off00010e34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001264b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1264B 11068 bytes
SHA-256: 55495822d73c8f3066cebeff1684f2fd96810d3accb07fb846636d2f0434fea5