Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6ed4cb5a171c1b4…

MALICIOUS

PDF

84.9 KB Created: 2021-09-07 00:55:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d48e0bd3448c4a377627e3c1ba2893ef SHA-1: 57aeb8db836c83dfce6d9f83a49a384213e34e95 SHA-256: f6ed4cb5a171c1b4111ea3738007fe76f3c4295108da842c2b67d5cbe23ed532
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm. The ML classifier strongly indicated maliciousness, and the structure aligns with techniques used to distribute malware or engage in SEO spam. No scripts were extracted, but the primary attack pattern involves directing users to external, potentially malicious, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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://drafthe.ru/uplcv?utm_term=mackie+cfx12+mixer+manual+pdf PDF link annotation
    • http://thaihotelsale.com/FileData/ckfinder/files/20210708_FAC37ABC6BAB14A3.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2e8cd6435---24250108683.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/wubitovusarebopexifikijig.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608e386ae1395---wanilaja.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/68804402388.pdfIn PDF document text
    • http://gdfsztal.com//uploadfile/files/16123085761.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607437ecaf5c4---vagebijegizipupedoz.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9e480452fe---25645513118.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3f9d7318f9---totukezutenobubufelowoxiz.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b5bd9a7f49b---9788554878.pdfIn PDF document text
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/jbrn1quj02hkchdqouk0100i2i/16972446231.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/3425653816.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/ir80b924aalo2lgpj36sn4otja/43336243333.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b82926dd6c1---nazewopuliwo.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1611e9c4df0669---55266669240.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/gn94tgjpba1pl380ev81vrtvan/17392112912.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/7decc04cece4aab364d5bc9220441ca9/20971404365.pdfIn PDF document text
    • http://mzch.pl/userfiles/file/pupuwumefazixaxevokajap.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/netabowirusudofewidoli.pdfIn PDF document text
    • https://ofertaromania.ro/ckfinder/userfiles/files/32244970698.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/farofijuxopabedofe.pdfIn PDF document text
    • http://smartraoptics.com/fck_filemanager_upload/file/govozetokuzotaline.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_off0000e293.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE293 10852 bytes
SHA-256: 697a11387608a6bfa14a7795dfb62e60dfaf91848a9e2c7bddf5a20f1c39320c
font_01_sfnt_off0000fbad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAD 18824 bytes
SHA-256: 656c77594c452ef79fcc21f3c5569c0704c09d3f53dc4c7aa6af7157161f233e
font_02_sfnt_off00012ca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CA3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1