Malicious PDF — malware analysis report

Static analysis result for SHA-256 253cf8ac3f9a04c5…

MALICIOUS

PDF

83.2 KB Created: 2021-09-06 13:11:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e2b9f9fc3f28a9640de279cced4cbe84 SHA-1: 4f71293abedfa2d135a9308e656f9811657b412b SHA-256: 253cf8ac3f9a04c56cdab5de0ecfebe36748b3ac8bf98687b7e55d4db346387c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple external URIs and link farm heuristics points towards an attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://mesterteto.hu/userfiles/file/vorunadipuselipafepat.pdf In PDF document text
    • https://manualismedicina.hu/fileok/file/37598671579.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/40c361e77fd1a57ee4a6e4b269564262/58631230511.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1611d22c2c3a22---wevezipovemuw.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/sizeginurizomefumuda.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160812ab5d6350---xomuzobolawawijexeb.pdfIn PDF document text
    • https://resonanceacteurs.nl/userfiles/file/lefatigivadumov.pdfIn PDF document text
    • https://marblobathware.ph/app/webroot/img/files/48044821189.pdfIn PDF document text
    • http://poetische-malerei.de/web/editor/files/tanaragatoxozug.pdfIn PDF document text
    • http://21cedu.com/pds/userfiles/files/bozujetelinuzaxagavizonip.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/ivqu5hua2v6dad69mukcpc2ltr/wuvinupapo.pdfIn PDF document text
    • http://fritz-fahrlaender.ch/download/63701459980.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/162485126965.pdfIn PDF document text
    • http://bhttourist.com/upload/fckimagesfile/xufataxutuna.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/22012858259.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609d52b70945f---3082807231.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/er9mqs77kkrfv9tkhnt42fmg3m/38388825275.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/ninumamemafarij.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4ea7d6e44b---88816042565.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d65d57d1d2---63170876456.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160defc53eddb6---xepexadurabo.pdfIn PDF document text
    • http://meghdoothsuzuki.com/uploads/zomipodi.pdfIn PDF document text
    • http://mppscstudy.com/admin/usercontent/file/bokanegabokozuxexa.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/7107482254.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/4831994437.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/buwafojujubavunob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=noten+river+flows+in+you+klavier+pdfPDF 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_off0000dc8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC8A 18624 bytes
SHA-256: 96d2912e5bf1442e2f906715c0d980e638782514b29e273966aab156027c008e
font_01_sfnt_off00010e05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E05 10928 bytes
SHA-256: 03507d2b42c880f32ec104cf0b9c090417c6611941def57e78457586ce44c907
font_02_sfnt_off0001278f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1278F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1