Malicious PDF — malware analysis report

Static analysis result for SHA-256 20537f213185e5c0…

MALICIOUS

PDF

71.8 KB Created: 2021-09-17 18:49:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bb5322d64507235947f41a1307d3408a SHA-1: 884415e433fa9eebabdd72f67cd838fd2c7872c2 SHA-256: 20537f213185e5c0d4f815e58ed3204f3a596e2eb6dca22277f444175cdf4363
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. The primary purpose appears to be directing users to a collection of other PDF files hosted on various domains, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613157795b556---kituvejejusujepolaxu.pdf In PDF document text
    • http://lg-palette.com/upload/files/12422187469.pdfIn PDF document text
    • http://snsi.jp/image/news_file/97588816705.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16130be663594b---68010946985.pdfIn PDF document text
    • http://ooexperience.be/assets/Image/files/49573254500.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/64836833521.pdfIn PDF document text
    • http://flamefitnessstudio.com/cewit/images/file/redejunulosime.pdfIn PDF document text
    • http://ckudzcssffhhj.handysociality.com/upload/files/22226381732.pdfIn PDF document text
    • https://faceless.me/userfiles/files/zufuw.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/kagedamogijezubowotol.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/46899008225.pdfIn PDF document text
    • http://china-hold.com/UploadFile/file/20210904002955053.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/17277462208.pdfIn PDF document text
    • http://nbmounts.com/userfiles/file/1631814721.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/vajudizol.pdfIn PDF document text
    • http://bigyikesmedia.com/home/xtremweb/public_html/consultinstitute/web/upload/files/99845321388.pdfIn PDF document text
    • http://braghieriarchitettura.com/userfiles/files/zilakujinisapiseze.pdfIn PDF document text
    • http://gocoachfox.com/userfiles/file/43402963607.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/81963253731.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/patere.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/rijarubifowe.pdfIn PDF document text
    • http://www.donboscovizag.org/images/files/jolezurezosewovod.pdfIn PDF document text
    • http://baohanhranghm.com/upload/img/files/64428300190.pdfIn PDF document text
    • https://homestayhoian.vn/uploads/image/files/xagiwot.pdfIn PDF document text
    • http://smingames.com/ckfinder/files/waravewezamevuduwevadu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=mi+box+pakistanPDF 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_off0000b508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB508 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD1A 17836 bytes
SHA-256: 31ddde12368d92f23df11fa649ac8006cecefcf68ff5e9608a053af4add6ec5b
font_02_sfnt_off0000faf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAF8 10292 bytes
SHA-256: f6bc1d66ab2ddd02a5543f1a17bea78a56fd907856ea9a6f4d30f381db93117a