Malicious PDF — malware analysis report

Static analysis result for SHA-256 523a1c3e8c9a679e…

MALICIOUS

PDF

88.0 KB Created: 2021-07-26 12:33:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 093f323d229c07b6b305b4a447710e23 SHA-1: 81ee214bc141c3bd92e75f703bbef2c51a06eff9 SHA-256: 523a1c3e8c9a679ed2e19f24fa8b9c3d877b535f74099b8a6dbf350ea157782d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a large number of links, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted from this sample, but the presence of numerous external URIs and the overall structure point towards a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://bularz-auto.pl/images/userfiles/file/lozitalesigupotoni.pdf In PDF document text
    • http://remont-etalon.ru/upload/files/60033719337.pdfIn PDF document text
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/1m930v30tgb7smf992u8m93afj/remelumaranajoxigotow.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/160927acbe9b89---6626388400.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160abdafcd8878---ratopokinig.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/38523211554.pdfIn PDF document text
    • https://trellisdundee.com/wp-content/plugins/super-forms/uploads/php/files/7690315a85648a72e397dd1a60d8cffa/86091687104.pdfIn PDF document text
    • http://ckm-machinery.com/userfiles/files/52411308936.pdfIn PDF document text
    • https://canevastoilestjean.com/upload/editor/file/19466683949.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/7786092856.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160877199cbc5c---mizepunudusetematevirowig.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16070730d40f13---35342856424.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/fe8d9bf20a4e4ca055d48036cac8f392/widilof.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/27182976654.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3f96277d65---90575587456.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1608f47d713192---kozamiwidilog.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/99a2c975c59f71efd15ebc30bf790341/gururujedonag.pdfIn PDF document text
    • http://color-gateway.com/userfiles/file/33047285314.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/rasitijiduru.pdfIn PDF document text
    • http://grabnerestriche.at/lekoxe.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/90855011a99df358e5b3c0597ead20b6/tetuved.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/52165883332.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160820f2351612---91865970481.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=fast+and+furious+7+free+download+full+moviePDF 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_off0000f1b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B9 17256 bytes
SHA-256: fb3128feddcbd0c1455b0b4e1044dce9ff1328a0ff08701d6f01fa4f70e7eaaa
font_01_sfnt_off00011eb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB9 10792 bytes
SHA-256: fad63021e21a17ca3a339c45aaee0f8723e40d6cebf78fea452969e69bc3fff2
font_02_sfnt_off000137b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1