Malicious PDF — malware analysis report

Static analysis result for SHA-256 941ef4478b1b51d2…

MALICIOUS

PDF

77.3 KB Created: 2021-10-09 12:57:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1b6896ae48a7b83a8a5bbe5a7faa730f SHA-1: 650e7f57c37e6fa37a14a5d75ebb55bc92c6dac7 SHA-256: 941ef4478b1b51d2b743f7c979e077e073ae1740c12f140c17d633f46ccb48ea
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to suspicious domains and are structured as a link farm, suggesting a phishing or malware distribution attempt. The presence of a 'download button' heuristic further supports this, indicating a lure to download a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://chung-pei.com/userfiles/file/sawalowobapesuzemekipime.pdf In PDF document text
    • http://www.ondebiz.com/userfiles/file/lagivobonuzot.pdfIn PDF document text
    • https://cryptoshift.be/anaeter_capital/siteadmin/userfiles/files/13337082846.pdfIn PDF document text
    • http://1yunnan.com/ckfinder/userfiles/files/vomurarepomasavenimubob.pdfIn PDF document text
    • https://altsovmun.ru/userfiles/file/muwumoxivubo.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/4870477477.pdfIn PDF document text
    • http://asacnfservices.com/ckfinder/userfiles/files/17022483904.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/82115855909.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/pozasuwawutivepatisu.pdfIn PDF document text
    • https://thebookonpersonaltransformation.com/FCKeditor/file/50221892300.pdfIn PDF document text
    • https://suncables.co/images/file/67382660827.pdfIn PDF document text
    • https://ventsistem-bg.com/userfiles/file/51879200918.pdfIn PDF document text
    • http://babyindex.nl/images/uploads/55405810565.pdfIn PDF document text
    • http://www.rodnolespropertymanagement.com/siteuploads/editorimg/file/sapisikomadinab.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/15751252885.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/sozovopumesovetibanonemu.pdfIn PDF document text
    • http://er-trans.com/img/produkty/files/34349592702.pdfIn PDF document text
    • http://china-guolin.com/filespath/files/20210919133009.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/lenafisolowoxitam.pdfIn PDF document text
    • http://hoangnampte.vn/quangbasanpham/app/webroot/upload/image/files/32828499542.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/zutolenetukalireno.pdfIn PDF document text
    • https://mldom.xyz/web/img/podborky/files/30756803183.pdfIn PDF document text
    • http://jadeite.ru/images/file/gobuzuvupukor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=hydraulic+lab+manual+for+civil+engineeringPDF 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_off0000c536.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC536 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4D 10964 bytes
SHA-256: 7159ed1a1a46f57d118a408e5696b85241b3cf01e0e95b1f5c061fc9c835f696
font_02_sfnt_off0000f673.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF673 18680 bytes
SHA-256: 1f1ca1fa5e54de6dbadae5d5928b78cfcbbc25aef4e5ec81f260ac9c8bc2e30e