Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fef1d832d833e94…

MALICIOUS

PDF

86.7 KB Created: 2021-07-30 13:26:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: de99da727d47f339d5f5804a8c323737 SHA-1: f32aac1f278180720639c7b841797811acbf3f09 SHA-256: 4fef1d832d833e94181870402665f1091720d70a28219459ab70176023fe910a
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://aymexco.ro/ckfinder/userfiles/files/kamofozojugadoja.pdf In PDF document text
    • http://5m-tti.com/uploads/image/files/jidanafemamisumosozi.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16076f47977aa7---romaretapiledabufizo.pdfIn PDF document text
    • http://sumterhigh89.com/clients/863574/File/60047705690.pdfIn PDF document text
    • http://richmediahouse.com/admin/uploads/file/bavedagukovumotafejategiz.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c196c867a0f---85242846766.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609486f446541---61086944351.pdfIn PDF document text
    • http://libron.pl/fckupload/assets/file/88178080008.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc40d285189---83277121017.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a40ff008a2c---buxamiruto.pdfIn PDF document text
    • http://contextuae.com/resimler/files/nexobibegiruva.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/ac431a0f6a8fd51882e08789fe47c8f6/41331158779.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c07bab8dd---jobimeb.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/db8273dad9d20da9daa25772b99f1833/91290433636.pdfIn PDF document text
    • http://axwelindia.com/uploads/xuzagibozur.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/g7rdfstbg62b7kedvguq1r2lt5/37808011534.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/95098220986.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/52686222942.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/kejepogat.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608562aa883f6---98063233398.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e6093f7ab---kobodijavilozafegudevidak.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c73f280c39e---rafezefumuvotazoki.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cae1e48d490---75227145603.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c09ff2fcb0---tanovoxenuborupaf.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/0d46d3a74df9248c3cfc652937767983/xalanukob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=solidworks+advanced+exercise+pdfPDF 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_off0000edb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB3 17220 bytes
SHA-256: bf3c6b8719bf2056289a6c1829dfef4542134a642c391175b1319684d182be42
font_01_sfnt_off00011aa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000132bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132BC 10936 bytes
SHA-256: b50f74fcd5c1aa9320240e24bd25e7e745b46505f9ede15c569b67157dac3b64