Malicious PDF — malware analysis report

Static analysis result for SHA-256 257626800015da39…

MALICIOUS

PDF

82.2 KB Created: 2021-09-12 11:33:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2499c86c3948dc222daf6ce84d21fba6 SHA-1: 86657164f92ad2c110f64dc82fd6869de83294ce SHA-256: 257626800015da398ab9f50c255e1ba8dcd7dcc52524aecee81c154f83ee3535
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://ooo-kenk.ru/userfiles/file/35009242218.pdf In PDF document text
    • http://spostojow.pl/userfiles/file/92149372639.pdfIn PDF document text
    • https://asmitahrgroup.com/ckfinder/userfiles/files/31547261367.pdfIn PDF document text
    • http://incomingmakedonia.com/files/files/mogosogafepejumupukuxazon.pdfIn PDF document text
    • https://spbmworld.com/anaeter_capital/siteadmin/userfiles/files/tomurubewijonezawerukido.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343deca8f55---vanatemuvavobiseri.pdfIn PDF document text
    • https://ideylia.fr/uploads/file/86672748539.pdfIn PDF document text
    • http://sushiosushi.com/uploads/files/tewuzuwazisozorebidosop.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/lizola.pdfIn PDF document text
    • https://machnhaduong.com/images/uploads/files/87790994505.pdfIn PDF document text
    • http://ed-union05.ru/files/file/32495690791.pdfIn PDF document text
    • http://fairfresh.net/assets/admin/ckeditorimage/files/25112506853.pdfIn PDF document text
    • http://styrexon.cz/userfiles/file/tasikadoga.pdfIn PDF document text
    • https://vokalensemble-vocembalo.ch/userfiles/file/28799160963.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/7882696951.pdfIn PDF document text
    • http://music-summer-courses.eu/upload/files/riwuvalodalazinu.pdfIn PDF document text
    • http://www.scsk12.org/policy/files/files/31577008027.pdfIn PDF document text
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/33517878565.pdfIn PDF document text
    • https://kccegis.com/upfiles/content/file/20210903235937.pdfIn PDF document text
    • http://scard.vn/app/webroot/uploads/files/jiveju.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc10580d65---83956387174.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/ml6e0up80hg4h6m1uoufnpue0k/41321073944.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/52278207796.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=watch+mulan+2020+english+subtitlesPDF 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_off0000db2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB2B 10932 bytes
SHA-256: f4e81476cf46decf18a728ce3789f39c9008b26523c942cac5956761afccfef0
font_01_sfnt_off0000f460.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF460 17996 bytes
SHA-256: d16ebf9b4a93799ff343b1a11f59318330cd78f741178129958022aa4935477b
font_02_sfnt_off0001232a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1232A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1