Malicious PDF — malware analysis report

Static analysis result for SHA-256 b93d053d9c58eb71…

MALICIOUS

PDF

71.4 KB Created: 2021-09-26 21:36:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 28c58aad18e3226d18b7be8a26b2f52f SHA-1: cb3c7c8c4628841ac69ac1b2ac81668fceb830b4 SHA-256: b93d053d9c58eb71f20c68329e6beea82ddd978673f18039c0d860e7fcff8b23
156 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics as containing a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document body is heavily obfuscated and unreadable, but the presence of numerous links suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://grandplaza.bg/uploads/assets/file/jabunirovu.pdf In PDF document text
    • https://santaclara.com/wysiwygfiles/file/xigolenanoles.pdfIn PDF document text
    • https://ozora.schaffsen.com/contents/file/59130576421.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/lowovaxanotuwo.pdfIn PDF document text
    • http://fernandopelosini.it/userfiles/files/1907993264.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210921095756.pdfIn PDF document text
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/41439349071.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/50ta9kfeho2bgoop35593adeqe/61965988647.pdfIn PDF document text
    • http://drumlockingclamp.com/FCK_Editor_Images/files/zupuru.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/e270e69d09df1efe8569860a9d83b45b/zesobifevo.pdfIn PDF document text
    • http://ageofwonders.buka.ru/sadm_files/40441335145.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161358fa3c8ca7---17049970403.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/51925727057.pdfIn PDF document text
    • http://hamdannepal.com/userfiles/file/newonadotedirivujataguful.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/fapabuzepumered.pdfIn PDF document text
    • http://giprozdraw.ru/ckfinder/userfiles/files/wadirifovesokovukima.pdfIn PDF document text
    • http://gidromall.ru/img/uploads/file/38829388097.pdfIn PDF document text
    • https://infrastone.com/userfiles/files/62872328457.pdfIn PDF document text
    • http://www.agenbenangbandung.net/file/vezakutuxegidawavafebexef.pdfIn PDF document text
    • http://lauraestetica.com/userfiles/files/rawozivinijigigukawixitem.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/rodidalipejow.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/befevefopusapideniv.pdfIn PDF document text
    • https://nergizleryapi.com/image/files/99531021755.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/42408333231.pdfIn PDF document text
    • http://yuqiaohome.com/uploads/files/202109051231021422.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=how+to+clear+network+cache+in+androidPDF 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_off0000b427.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB427 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC3E 10468 bytes
SHA-256: 3d79bff349062a17e2e7717a4be3950db22197cfda46441245e94e41fe1017e5
font_02_sfnt_off0000e3e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E8 17128 bytes
SHA-256: e197e5ad2a0dee443a461b41df8ce20de5461f3a7b8c2e618fad306e0f81bcbd