Malicious PDF — malware analysis report

Static analysis result for SHA-256 65bf26f44a5357f4…

MALICIOUS

PDF

82.2 KB Created: 2021-10-20 21:01:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: dee6b81d9d1b100a7af440c040337f79 SHA-1: fc1e078a214b73de84bdab9fdb786b2f5aee818e SHA-256: 65bf26f44a5357f4d99add6f49052b761894b770913ccd13cf2abae7636a7210
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, indicating an attempt to redirect the user to malicious or SEO-manipulated content. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm on compromised CMS upload storage further supports malicious intent. The embedded JavaScript likely facilitates the redirection or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • 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://coretry.ru/uplcv?utm_term=stomach+and+heart+burning PDF link annotation
    • http://zhihepvb.com/upload/ckimg/files/202109061023574141.pdfIn PDF document text
    • http://www.centralperdana.com/file/pakuxejokimowanarip.pdfIn PDF document text
    • https://kovrdom.ru/sites/all/sites/default/files/file/11561528609.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16159d14a7a5ee---49820422384.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1616ce21874953---dowimejugopopenurerafe.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/riwepinuvobe.pdfIn PDF document text
    • http://studiopetrilli.it/userfiles/files/rowagovama.pdfIn PDF document text
    • https://anzhero-sudzhensk.verlauf-ekb.ru/admin/ckfinder/userfiles/files/toridifiwubofivovevizoxeg.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/vogozofemadis.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/35878358702.pdfIn PDF document text
    • http://azco.friend-match.com/upload/files/negazuwivevipes.pdfIn PDF document text
    • http://falegnameriacastiglione.it/userfiles/files/44164261821.pdfIn PDF document text
    • https://viveironativodevicosa.com.br/ckfinder/userfiles/files/fesim.pdfIn PDF document text
    • https://qnzar.com/files/36664511638.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/penewifafatupek.pdfIn PDF document text
    • http://autostyle-japan.com/js/upload/files/60327886003.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161351a1a327a5---vugege.pdfIn PDF document text
    • https://tomas-music.com/contents/files/vuveduga.pdfIn PDF document text
    • http://lacasedescaraibes.fr/file/napefabizugilasigasu.pdfIn PDF document text
    • https://cepatdaftargroup2.com/contents/files/begotirifi.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/pumukavipu.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/sefudobiremejijam.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613fedbc27662---sazodolo.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_off0000db13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF325 18148 bytes
SHA-256: 80b7b8fccae84a4c9ba8983b63ccce222134691b70c3b2c4b1ff193aa8c0a1f4
font_02_sfnt_off000122af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122AF 10916 bytes
SHA-256: 69cf09de26d02b277534c78eb1964b04bdf872aaad26a10907dac6b2fc90fdd9