Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fc4577f3fcda3ac…

MALICIOUS

PDF

100.9 KB Created: 2021-09-13 05:10:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 22ddb1596e6b57fcb5a42c7907cdadeb SHA-1: 424a361eca8b6466cc81fc9635f31f7961cfa6e1 SHA-256: 4fc4577f3fcda3ac1062fc7a18de8c873135275541d236ea1d136b908177e3c3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO poisoning by directing users to a network of potentially harmful PDF documents. No scripts were extracted, but the PDF structure itself is indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9803

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vswet.ru/f/sumiravunivuxegim.pdf In PDF document text
    • https://dom4m.de/userfiles/files/31783184570.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/17311895404.pdfIn PDF document text
    • https://sarna-zapiekanki.pl/ckfinder/userfiles/files/27983705715.pdfIn PDF document text
    • http://abogadosaguilar.com/ckfinder/userfiles/files/39149842601.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/vigogeviwotewilozalula.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/56514785521.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/mariwasusirimatolujudafa.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136f36360f8c---lamufovor.pdfIn PDF document text
    • http://thegioidahoacuong.com/uploads/image/files/madebuzatogijudukus.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/wozigagareta.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/wivegulotafeve.pdfIn PDF document text
    • http://ageofwonders.buka.ru/sadm_files/wamelijunaboxi.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/sewesizumati.pdfIn PDF document text
    • https://rentcar888.com/uploads/files/202109020552487145.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/tubonaturaxapaberarosomo.pdfIn PDF document text
    • http://akpanlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/juzitifumi.pdfIn PDF document text
    • http://piazzademarini3ge.com/userfiles/files/zawuzis.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/57273589731.pdfIn PDF document text
    • http://fabiocaronearchitetto.com/userfiles/files/ganakejetubovavizik.pdfIn PDF document text
    • https://mytshirtcreator.com/app/webroot/files/file/notada.pdfIn PDF document text
    • http://multiflex.ru/userfiles/file/83233526796.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/senixazamenijinaxuzovaj.pdfIn PDF document text
    • https://ncvpte.in/userfiles/file/69011325057.pdfIn PDF document text
    • https://www.adoz.cz/ckfinder/userfiles/files/63746071117.pdfIn PDF document text
    • http://xn----otbbfbbknchz.xn--p1ai/sadm_files/18791845189.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=highest+incarceration+rates+in+the+worldPDF 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_off00012477.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12477 10724 bytes
SHA-256: 5a5f8d29583ce2b0f33516f2d0d940f1e671d8dbf9d971a0b308363b3444cd99
font_01_sfnt_off00013cdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CDD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000154ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154EF 18660 bytes
SHA-256: e6db881364260736d324480c2363090159d9257bd0049bac63300a8c921b7196