Malicious PDF — malware analysis report

Static analysis result for SHA-256 25376764457b9303…

MALICIOUS

PDF

85.0 KB Created: 2021-09-09 11:25:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6f8d02a83aee6c3b236d747710bb7b1a SHA-1: 8beed99cb76c485fdde657f4db39007e0e4919ea SHA-256: 25376764457b93036d95d0c2e197d526662940666d9da1c1f0170b96a5f967b2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external resources, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading further malicious content. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://jljemc.com/upload/files/92493310062.pdf In PDF document text
    • http://asiadomainstore.com/userfiles/file/didivubix.pdfIn PDF document text
    • http://agavietnam.com/img/files/falewevulex.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/3064134155.pdfIn PDF document text
    • http://ddservice-bmw.pl/userfiles/file/zofol.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613319f14e487---58447569951.pdfIn PDF document text
    • http://totoumi.jp/upload/file/30810635713.pdfIn PDF document text
    • http://5percent-design-action.com/upload/users/files/31509060595.pdfIn PDF document text
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/xefije.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/tawepalanuzidudixigi.pdfIn PDF document text
    • https://eclearusa.com/images/file/waropirajawidaf.pdfIn PDF document text
    • http://jadever.vn/Images_upload/files/sadow.pdfIn PDF document text
    • https://trungtammatnamviet.vn/upload/files/75986938815.pdfIn PDF document text
    • https://xn--80ag1a2a.xn--p1ai/files/file/zipatofi.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/guvemewamuxe.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/pepizadoresimujini.pdfIn PDF document text
    • http://instalater-macecek.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/28443279278.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/nufulavu.pdfIn PDF document text
    • http://shacklefordlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/puwif.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/75033394291.pdfIn PDF document text
    • http://infinity8talents.com/userfiles/file/bugututu.pdfIn PDF document text
    • http://artattack-concerts.de/files/file/97646243829.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=escape+room+full+movie+downloadPDF 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_off0000e6b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fecd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECD 10916 bytes
SHA-256: f26fa10e5edff393d9b44fa928ea9cc0be2af59e5f1ebfa6488849dd6e9c38e8
font_02_sfnt_off00011818.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11818 17956 bytes
SHA-256: 6fe65b077f460c9086572cc8de82b83dac7039d00fad3f4fc3b84fac675eeaf8