Malicious PDF — malware analysis report

Static analysis result for SHA-256 921ff5c353490be2…

MALICIOUS

PDF

84.1 KB Created: 2021-08-29 19:29:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d30cb1dba3e04bbca9a6ec1656e458c8 SHA-1: ce7c2725c9f7686a578244b9bb334b87a432a25e SHA-256: 921ff5c353490be24a626c064e4d0e4af39ad3e856a917cabe8429c8d3d6a6d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm directing users to numerous external websites, with several links pointing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the URL analysis and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://sicilyontable.it/userfiles/files/89895150862.pdf In PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16073e72616d7c---fubomorijo.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160bd63cc7d938---mekijaw.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/51968439863.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/79c3a20496f773aba8aca8c8698864b2/53097247948.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b55f5332b09---pikoxuzetitolezemenawid.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/81427766166.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc662abf7de---waziba.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/jizuzixulogeforevatediv.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/0b65865146368fcf2cca61f8a4200fd8/24372775940.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021070208515963.pdfIn PDF document text
    • http://best-infosystems.com/userfiles/file/39269143589.pdfIn PDF document text
    • http://taborcapitalpayment.com/clients/d/d0/d0a3925ee25d0adc8806453b18bccccc/File/43769741889.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ddb5950650e---nezuzati.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/vavikonupezepusese.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16072871a82c36---39796823220.pdfIn PDF document text
    • http://railwaysrailroads.com/upload_files/files/fubawepizegozumubo.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160caac298e677---80613306535.pdfIn PDF document text
    • https://feldmann-spedition.de/pics/userfiles/file/pemuzuvatupokigufagizoj.pdfIn PDF document text
    • http://pvhs1967.com/clients/a/aa/aa78cb05297cd93d8a9ab6bd1eb8a3c4/File/6644225893.pdfIn PDF document text
    • https://transturist.ba/ckeditor/ckfinder/files/files/58236104338.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076cfacc36e4---38839821997.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/f1b1f7a98394b126ecc31c928f602639/guvekukedawasa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=simple+present+tense+online+testPDF 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_off0000e49d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE49D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fcaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAF 18224 bytes
SHA-256: ca8776ea3fcf7a4f13c39007c577f9175fd1403e96fc6255f35ac9b520b7a36b
font_02_sfnt_off00012b50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B50 10324 bytes
SHA-256: 1d317c05d0032428169025299423a6d6e5c27aa6d3a69f16bc35ab02143c0c15