Malicious PDF — malware analysis report

Static analysis result for SHA-256 f633b9d8c5e3c494…

MALICIOUS

PDF

72.9 KB Created: 2021-10-01 16:10:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dd8cd3b32b0976cdbf32f7af0b4da610 SHA-1: e9bf1e858e6883c8d37d7b015ceedf5aa90290d6 SHA-256: f633b9d8c5e3c49414f3c892c66a491f255e44159fbad904f2c0572cccbc01b7
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, with one heuristic identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery via the embedded links. No specific family could be identified.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://splogservice.ru/content/file/85278899720.pdf In PDF document text
    • http://chelseafoodmart.com/uploads/files/guxufesasukexija.pdfIn PDF document text
    • https://safetypadlocks.eu/eurostyl/photos/file/simevodereju.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/fekuniwol.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/38277473191.pdfIn PDF document text
    • http://pusancard.com/userData/board/file/megunizekarilixofaku.pdfIn PDF document text
    • https://gestcargo.com/uploadfiles/file/89001080026.pdfIn PDF document text
    • http://lingvastar.z-i-g-z-a-g.com/userfiles/files/dorejugosipibevosofejub.pdfIn PDF document text
    • http://knshzj.com/CKEdit/upload/files/52846071524.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16146d8451f72f---79226774207.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/vuzilak.pdfIn PDF document text
    • http://tech-sub.com/userfiles/file/wozurevufigasesojida.pdfIn PDF document text
    • https://immo-macedo.lu/userfiles/files/zukama.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/21472933893.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210915204627.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/35733579839.pdfIn PDF document text
    • https://chinatupai.com/web/js/ckfinder/userfiles/files/35719171425.pdfIn PDF document text
    • http://poketomecam.com/uploads/files/zoneludarum.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e139bc5c013697805e64c129717b5adf/16224256804.pdfIn PDF document text
    • http://mai-colle.jp/userfiles/file/segamofegowedudakadave.pdfIn PDF document text
    • http://greddy.com/admin/common/ckfinder/userfiles/File/zililoloruwupop.pdfIn PDF document text
    • https://jeevadhara.org/work/london/userfiles/file/48203177386.pdfIn PDF document text
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/bifiwuxalenojuparogonup.pdfIn PDF document text
    • https://nepaltravelsandtrekking.com/userfiles/file/kekakulawojukokiloduvam.pdfIn PDF document text
    • http://www.mecateengenharia.com.br/ckfinder/userfiles/files/23405873058.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=voice+dialer+android+bluetoothPDF 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_off0000b536.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB536 10508 bytes
SHA-256: b493bd5250b51abcf768c5eac439a32de99b0fd676a5b626cc934cf79c7acdbe
font_01_sfnt_off0000ccfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e510.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE510 18712 bytes
SHA-256: 5f9bf9de3a3abfd81d85800261f1278bfbec0066949d6a9d3d0159e35e278944