Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf8fde9b3febf3a9…

MALICIOUS

PDF

78.3 KB Created: 2021-09-20 17:53:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 71e6439b5727569632115e9a651097a0 SHA-1: 0c30f40fcd8fff1b6b10129f6db990fe9dad7b5b SHA-256: bf8fde9b3febf3a93a6083b9f1b33fd093e7740309494d4a8b1f7939c9423803
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains embedded JavaScript and a large number of external URIs, many of which point to potentially disposable hosting. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm on disposable hosting, suggesting a phishing or malware distribution attempt. The embedded JavaScript is likely used to facilitate the malicious activity, such as redirecting the user or downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://profitoolinfo.ru/ckfinder/userfiles/files/51713224241.pdf In PDF document text
    • https://isleo.com/i_photos/file/nufefekabexi.pdfIn PDF document text
    • http://portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/36164554466.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/41250798185.pdfIn PDF document text
    • http://aktifbant.com/resimler/files/47506053868.pdfIn PDF document text
    • http://cosmeticdermatologymiamibeach.com/uploads/data/files/80205516816.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/53072487549.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/renirobe.pdfIn PDF document text
    • http://jorkurojus.com/userfiles/file/xebibuf.pdfIn PDF document text
    • https://vialivonica.eu/userfiles/files/45536287465.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/78648515023.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/finodenukovexemovag.pdfIn PDF document text
    • http://ssp.by/var/upload/8979773972.pdfIn PDF document text
    • http://special-pharma.com/upload/files/72894711679.pdfIn PDF document text
    • http://chothuexehochiminh.com/userfiles/file/vivusuwosim.pdfIn PDF document text
    • http://esistore.com/userfiles/file/45343277496.pdfIn PDF document text
    • https://buffinvestment.com/upload/ckfinder/files/50317964933.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/gozit.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/zeweta.pdfIn PDF document text
    • http://www.lovebliss.tw/UserFiles/files/84522043938.pdfIn PDF document text
    • http://fruitsad.pl/images/file/69882806436.pdfIn PDF document text
    • https://poganyvolgyi.hu/userfiles/file/5333219943.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/061125383997.pdfIn PDF document text
    • https://aczv.fr/userfiles/file/gifuzuwirosudixigomas.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/80050089060.pdfIn PDF document text
    • http://lyzjkgm.com/d/files/15565604634.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=betsy+braddock+psylockePDF 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_off0000cab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAB9 10712 bytes
SHA-256: 2e7779b9165d1d37ec0ba4547f03c8288636d71cda0113ce4497b462d3780643
font_01_sfnt_off0000e35b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE35B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB6D 18280 bytes
SHA-256: 700a453b11c73be59cd342b613061ef2f9acdb116e7e383cb9c782216dc75a23