Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbb735398e4bf7d3…

MALICIOUS

PDF

69.3 KB Created: 2021-09-25 13:49:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7cce80b2e85466d2d7b2f853584f1eb3 SHA-1: fe0d6aa6dea12bf9e2152c8b290bcdef128fd49b SHA-256: dbb735398e4bf7d3a7618ed933efbdc7b6fa8296e274af87ab646ee3895638d0
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm. The embedded URLs, despite some being marked benign, point to a pattern of hosting numerous PDF files on disposable domains, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggests the intent is to redirect users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://corising.info/sa_upload/userfiles/file/20210914103758.pdf In PDF document text
    • http://rebeccafantarchitetto.it/userfiles/files/dojirajulasemidefanit.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210903_000845.pdfIn PDF document text
    • https://faktxeber.com/resimler/files/16665630493.pdfIn PDF document text
    • http://sedaciesupravy.sk/media/file/38873459988.pdfIn PDF document text
    • http://abwmechanicsville.com/uploads/files/vokavexotugexolip.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/files/ziparapal.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/55018553446.pdfIn PDF document text
    • https://autopits-directo.migrupoq.com/ckfinder/userfiles/files/63665933670.pdfIn PDF document text
    • http://hpcad.pl/Upload/file/wipaginuxutogetegofan.pdfIn PDF document text
    • https://fancybox.pamlskovnik.cz/ckfinder/userfiles/files/vatibeguso.pdfIn PDF document text
    • http://spc1991.com/ckfinder/userfiles/files/17207493780.pdfIn PDF document text
    • https://bdata.vn/upload/files/neregebevisu.pdfIn PDF document text
    • http://autoescuelatosal.com/galeria/files/kukekum.pdfIn PDF document text
    • https://inprovitbolivia.com/ckfinder/userfiles/files/87673547847.pdfIn PDF document text
    • https://ka-base.no/images_content/file/deradewo.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614080cc36b04---68657983534.pdfIn PDF document text
    • http://hwayoung.kr/upfile/files/wipojudapaxerametawaropu.pdfIn PDF document text
    • http://compufoxmail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/62295033882.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/37810287949.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/tofibogoxuxis.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/zurapusuzarokabekuxomevu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=moving+wallpaper+hd+downloadPDF 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_off0000aef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEF1 10552 bytes
SHA-256: 89b20ba98877c77e4fab821d0586e03f1cc36efe8921070ca70bbf8fe50ad81f
font_01_sfnt_off0000c6bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6BB 15948 bytes
SHA-256: f2c0e7efbb699cb74c2b3b52a353a5c0c74b056a09a90bf9e034b91ebfeaf257
font_02_sfnt_off0000ef9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1