Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b851850ff1abd0e…

MALICIOUS

PDF

71.9 KB Created: 2021-09-27 11:13:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a3bb6614c7d7b1aa9a1471a6a5cad6a6 SHA-1: fd20b5987d15d7b62bbb6e4c9907aa0d7eef2ef2 SHA-256: 2b851850ff1abd0e2beb953e0c9a20f897b4f925baa90f340c44d15cf4dac7ae
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious intent. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest the document is designed to redirect users to potentially harmful websites. While no scripts were explicitly extracted, the nature of the PDF and its embedded URLs strongly suggest it's part of a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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 https://inwebjor.ru/uplcv?utm_term=android+launcher+without+app+drawer PDF link annotation
    • http://thoitranglani.com/upload/files/39074630165.pdfIn PDF document text
    • https://groupburuemas2.com/contents/files/junesewisubigaz.pdfIn PDF document text
    • http://yves-segers.be/userfiles/files/lagomufukonibinanup.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/83285939750.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/68443306544.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/87612285852.pdfIn PDF document text
    • http://falconltd.pl/cache/file/2866678235.pdfIn PDF document text
    • https://vetregistr.com/ckfinder/userfiles/files/93143941379.pdfIn PDF document text
    • http://ychnjl.net/userfiles/files/10133623451.pdfIn PDF document text
    • http://hanyangsteel.com/files/fckeditor/file/1375298476135689d52b84.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16142b0f33468f---suvijodazajitaxopapakove.pdfIn PDF document text
    • https://vientangluc.com/upload/files/tabofavevuzovumazelepizer.pdfIn PDF document text
    • http://saeronbio.com/userData/board/file/rulaxeposizaziputazutof.pdfIn PDF document text
    • http://vititanon.com/user_img/files/gowogovoxuviza.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cfe355872f---sopodode.pdfIn PDF document text
    • http://nordicwalkingturak.hu/_user/file/suxuxuxukadunit.pdfIn PDF document text
    • http://dentalclinicbangalore.com/uploads/54284220562.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/sixadotajabu.pdfIn PDF document text
    • http://suurelepa.ee/data/file/molatujufajurunabibezuzu.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/96800381837.pdfIn PDF document text
    • http://eskuvoiiranytu.hu/blog/file/vigajipejosid.pdfIn PDF document text
    • http://urgentcarepb.com/userfiles/file/65861332877.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/vedupijefoxutiwebek.pdfIn PDF document text
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/sawiki.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/84492286273.pdfIn PDF document text
    • https://rafaela-motores.com/userfiles/file/wotegawuxitizobe.pdfIn PDF document text
    • http://brukikostka.pl/uploads/page/file/tomoka.pdfIn PDF document text
    • 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_off0000b617.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB617 16704 bytes
SHA-256: d9ebfea169a3864408cd164e05940746ec92a43e7fdc9ffae4fe4a1931a500f7
font_01_sfnt_off0000e0b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f8ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8CE 10608 bytes
SHA-256: 3e304e6f6bec6e366ab7158f5c70de74c75b8fb9d173d5c569d16a4f30fa0f62