Malicious PDF — malware analysis report

Static analysis result for SHA-256 586e38571e936fa9…

MALICIOUS

PDF

69.5 KB Created: 2021-10-02 23:47:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 283d8ea59ece2429ec8e4219c0b559ea SHA-1: c1090c4349eb10f0ed52ac13062d5ddce1ebc6c0 SHA-256: 586e38571e936fa9cf3754eded7fde36d6e5d0efa7e87e2df4da89252899c5af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using such sites to obscure the ultimate destination. The primary attack pattern involves directing users to external URLs, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

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 https://irlanc.ru/uplcv?utm_term=race+in+usa PDF link annotation
    • http://thucphamchucnangmy.vn/uploads/files/75271415615.pdfIn PDF document text
    • http://tortsurprise.ru/upload/redactor/files/taruzogubi.pdfIn PDF document text
    • https://bak.vn/upload/files/ligitepapulisovisazetuso.pdfIn PDF document text
    • http://gramercy-grand.ru/files/file/fozufamanafenomebivuxuz.pdfIn PDF document text
    • http://myslizdrave.com/soubory/tufuwef.pdfIn PDF document text
    • http://sensitiva.fi/UserFiles/File/76098324346.pdfIn PDF document text
    • http://yoron.net/up/files/70777833781.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/foxinuzifofumedubadip.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/96105198c89ad52aaa1b6ac28e691605/10859086372.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/92d73bda8b18321c2ffb5b5735c81042/gubipupozowoj.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/26514912387.pdfIn PDF document text
    • http://tfe-design.dk/userfiles/file/8952053566.pdfIn PDF document text
    • https://proetcontra.hu/userfiles/file/zevubupu.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/47687946997.pdfIn PDF document text
    • http://www.bluewhaleline.com/image/upload/File/27137277688.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/mapubidizow.pdfIn PDF document text
    • http://imobiliariaimperio.com/files/files/79894750678.pdfIn PDF document text
    • https://madame-tina.com/ckfinder/userfiles/files/35800498619.pdfIn PDF document text
    • http://bancodevida.com/bancodevida/admin/images/image/file/fimesepakuberuk.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/kononanazuvuwiwoduz.pdfIn PDF document text
    • http://mabifitness.it/userfiles/files/5224543125.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/5l59bmmvai65no0kh0fk6cs154/lavigegide.pdfIn PDF document text
    • https://fratellifurloni.it/file/semekugetomirap.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbc2c211c0---rexopiledujuvijoti.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/teguxadenomaxulodevep.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/52018270580.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_off0000b133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB133 10004 bytes
SHA-256: 139510ea8e5161dd21022958dd8be7c55a3fd1e1532c220a0deb6823bfa7afc8
font_01_sfnt_off0000c77b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC77B 16024 bytes
SHA-256: b00c689453bb37d0654801853dd44b98f61440adf06509d558b58c48c672c412
font_02_sfnt_off0000f0a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1