Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4d5aa89b5903ebd…

MALICIOUS

PDF

69.8 KB Created: 2021-09-25 16:57:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 5420d000c59d5ae61e5d555afa37b0f1 SHA-1: d350c111e7e5e08c567e070ec2cceed9ce2854cd SHA-256: f4d5aa89b5903ebd279089d8cf8e3dbfb7935dfde25f6df0a9c2312c521db38b
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting. The ML classifier and ClamAV also identified it as malicious, likely a phishing or malware distribution lure. No scripts were extracted, but the embedded URLs are the primary indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://biogenetec.tw/image/files/20210919_223458.pdf In PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614e79a6d5b08---6753898330.pdfIn PDF document text
    • http://conniecorsentino.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nusesuwaxinok.pdfIn PDF document text
    • http://wannawwannie.pl/userfiles/file/fewutetopenalogoviji.pdfIn PDF document text
    • https://tw-itemaos.com/ckfinder/userfiles/files/75101621665.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/e32ec9df45527ad70b213489f870b6da/xazozobebin.pdfIn PDF document text
    • https://najlepsze-w-polsce.pl/uploads/91311319218.pdfIn PDF document text
    • https://dnm.tw/uploads/files/202109041118113273.pdfIn PDF document text
    • https://distriparkbotlek.nl/userfiles/files/pabunuvubixetakom.pdfIn PDF document text
    • https://insp.biz/img/file/kuvajibesojolujudi.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/95904116403.pdfIn PDF document text
    • https://verredistri.fr/xmedia/file/sizitipetadaboj.pdfIn PDF document text
    • http://nhatrangpalace.vn/app/webroot/upload/files/62573829839.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/upbt3lda16bj21n614e3c96p61/lonilegekejesujujojato.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/detefiwupuxezikugivuwid.pdfIn PDF document text
    • https://unitedpetexpress.unitedreloth.com/ckfinder/userfiles/files/mamoropixegituposonetinad.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394cfd717c9---1464612743.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/66910795780.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161470dbd08981---pesedakoxetot.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/jesupozatufumaxezew.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/71571280007.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/gumipuzosutibobumixakuwa.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/18714541105.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=tv+output+software+for+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_off0000b252.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB252 10660 bytes
SHA-256: d1b6ab8760ec7b01c823d36c16412914b3d7cfe8df67011f8a426ec110f1e3f3
font_01_sfnt_off0000cafd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e30f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30F 14672 bytes
SHA-256: 0e10955d722941771a31bfdfeb9267fe0cfb29382f524a1d2b58c794dbfcfad2