Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b53a8f8a093d494…

MALICIOUS

PDF

122.9 KB Created: 2021-07-04 15:42:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 258710665296fce12abbc1d0f4d6ac41 SHA-1: 6ef4d92d8ca1ab738d7baa9c8ea09ea2b52c09d5 SHA-256: 8b53a8f8a093d4945abbdf667e4c18c3edaad0ceeed495457d51cd1e3e011899
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised WordPress sites, identified by heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded links likely serve as a lure to download further malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/8c8cc94aea60c3a0a7ebdffd56f7415d/84844026085.pdf In PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2bf45d96d---jelebutuzumebeda.pdfIn PDF document text
    • https://ystechpro.com/nbloom/fckuploads/file/8398638323.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160718f64e2d18---30825422566.pdfIn PDF document text
    • http://topoint.cc/userfiles/fckFile/20210629202754.pdfIn PDF document text
    • http://drapa-technika.cz/UserFiles/File/1276391546.pdfIn PDF document text
    • http://autoscuolauniversale.it/userfiles/files/55931900972.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1e78b80572---53805291562.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b3fa1e9f941---nakilinafudapuduxoze.pdfIn PDF document text
    • https://acavacecio.it/userfiles/files/62455568900.pdfIn PDF document text
    • http://allg-gyn.ch/userfiles/file/divuxiridenozujikitaloju.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160888b1c01a67---katisodemever.pdfIn PDF document text
    • https://genericdiabeticteststrips.com/userfiles/files/vonafuxunubovadipu.pdfIn PDF document text
    • http://angelcabrera.com/FCKfiles/file/63899844123.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/bl16693umnrm9kkek2q7svdfgp/26948307420.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc7b5826e5---rumijirumudevul.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/kubudekolo.pdfIn PDF document text
    • https://observatoire-omic.org/documents/file/56432974585.pdfIn PDF document text
    • http://www.kmclogistics.com/wp-content/plugins/super-forms/uploads/php/files/b6a2d808bb5164cde5ee3ede52a6e22e/masipuw.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/16994143614.pdfIn PDF document text
    • https://boyanbolyarski.com/userfiles/file/6792968562.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/0e605c9386479d754d7d034c0c669989/dobowenapipapururudu.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/jdv8n87hr2tcokvgsomat2r4qf/xegupituroxaxilaf.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af7ae7153a4---sojefipumediwizabu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=the+ventricles+arePDF 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_off00017a91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17A91 20236 bytes
SHA-256: ff6615d4a6a9f4a56184ecd11ee2aea9109cca824bd28b4be84c673d4f594869
font_01_sfnt_off0001af29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AF29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001c740.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C740 10236 bytes
SHA-256: 8481b1a542ce2b357cf227588132539cc0b8e27a836f973411f945d60f38e14e