Malicious PDF — malware analysis report

Static analysis result for SHA-256 af6597556edd6f39…

MALICIOUS

PDF

82.6 KB Created: 2021-09-21 11:27:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b880eba27f3c7a5da75debf5d576895 SHA-1: 65fb966f0d8056afac1a68d4c968acec41b1bbde SHA-256: af6597556edd6f399a893f588da5c22265c54233814022a4c7e8aa5af9d691cf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites, which are designed to deceive users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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 https://sklepbonus.eu/userfiles/file/naxizuxobuduwi.pdf
    • http://stringquartet.biz/web/images/fck/file/66973079221.pdf
    • https://nicklason.se/ckfinder/userfiles/files/82034542015.pdf
    • http://deborahkay.com/ckfinder/userfiles/files/gorigibalasibilezo.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140caf0bdcf1---63187790351.pdf
    • http://ateliergermain.club/sites/default/files/file/44991782601.pdf
    • http://circolosilverblufitnessclub.eu/userfiles/files/famopututifoxu.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f93397cd41---59463062378.pdf
    • http://technestudio.eu/userfiles/files/67750271560.pdf
    • http://venusland.vn/app/webroot/img/files/pijubipo.pdf
    • https://namkhoasaigon.vn/web/images/files/88379389881.pdf
    • http://www.beautyvogue.ch/Files/file/57879585311.pdf
    • https://accounting789.com/ThImg/file/kebixolegeviwu.pdf
    • https://lean-ds.com/upload/editor/file/35977859606.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16146257296aea---jubomufuja.pdf
    • http://isleford.com/filespath/files/20210902125911.pdf
    • http://finalstage.biz/js/upload/files/wuvigukodarigelimaviku.pdf
    • https://rajatotogroup2.com/contents/files/49291741658.pdf
    • http://luyutea.net/v15/Upload/file/2021920180581521.pdf
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/2109060058308245001bdi1y.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16144bbf8b2d46---wepopuwutudovan.pdf
    • https://rcot.org/userfiles/file/gemotugu.pdf
    • http://mexvp.com/ckfinder/userfiles/files/xedigijokijus.pdf
    • http://avalon-essenzen.at/userfiles/file/bobajit.pdf
    • http://cwpni.com/userData/ebizro_board/file/55473211002.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/e889pcbdss40d66376j0et8t95/zedekov.pdf
    • https://braus.uz/images/shared/file/28630213490.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=unblocked+minecraft+online
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df1d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1D 16792 bytes
font_01_sfnt_off0000f734.bin
10304d76a8eddffadf4806d3773b764a27988e3aa521a107ab68cded665b125a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF734 10708 bytes
font_02_sfnt_off00010fb7.bin
526d30e98aa00422697c5f49731ebbe8d1f4b0777b11ce35876d8dd19e1ffc80
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB7 17420 bytes