Malicious PDF — malware analysis report

Static analysis result for SHA-256 20f5c38f5a32e159…

MALICIOUS

PDF

84.4 KB Created: 2021-09-18 11:22:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 86833f7fb0c4354202709f6238b513ea SHA-1: 9aa8da91d24bbd65b516099a66e09a0c65991a4e SHA-256: 20f5c38f5a32e1592f90b4f0125d3949fc9b64cbaafec474771e937ba71d594a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://history.tlshaa.org.tw/ckfinder/userfiles/files/335003758.pdf In PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/11/72154738554.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/legosifenanolakababen.pdfIn PDF document text
    • https://geya99.com/ckfinder/userfiles/files/tezove.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613237dae0f22---ponofowuwaxobumo.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/37534342502.pdfIn PDF document text
    • http://artechq8.com/beta/uploads/files/57988510433.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/files/files/62796695722.pdfIn PDF document text
    • https://tlproduct.com/userfiles/file/92599588044.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/34681552917.pdfIn PDF document text
    • http://faceconnects.com/ci/userfiles/files/73374805523.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__612FD45661B5F.pdfIn PDF document text
    • http://beta-rc.com/upload/files/74657771177.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/49525658c5149e1a9518e251e8082766/33522580968.pdfIn PDF document text
    • http://scuderia512.com/js/upload/files/zeketikap.pdfIn PDF document text
    • http://ordineveterinarireggioemilia.it/userfiles/files/buluwozuxadagavapejukep.pdfIn PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/31637018990.pdfIn PDF document text
    • https://srldirect.com/ckfinder/userfiles/files/tijasovaripajuluxule.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/joxis.pdfIn PDF document text
    • https://borgopitti.it/userfiles/file/93923148392.pdfIn PDF document text
    • http://dienmaythanglong.org/uploads/files/24965260226.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/1452390513.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202109131731417206.pdfIn PDF document text
    • http://schubert-hh.de/image/file/24811012854.pdfIn PDF document text
    • http://konberdbio.com/upload/files/vigemosewevaxut.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=yugioh+card+game+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_off0000e81a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE81A 10696 bytes
SHA-256: 4c179037d62b40386086b9ece282f7243b877878cdab11c8c21a643089c0b717
font_01_sfnt_off00010034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10034 17028 bytes
SHA-256: e13c0f5259237a618337efe46ccf9a481f4f22f2c0edc5441ca3ced3dc6bb7f1
font_02_sfnt_off00012c1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1