Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8c67d6dceb93951…

MALICIOUS

PDF

86.7 KB Created: 2021-07-05 08:08:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 635e9b067800c5d64663d90ac3c40c67 SHA-1: 809d0dc1247881ba683869d4bcc608a94bf4e4de SHA-256: a8c67d6dceb9395151f2924fcf06e6ef31780037cf5d6b40fde6a744da7958b5
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress installations acting as hosting for the PDF files themselves. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of link farms on compromised CMS uploads suggests an attempt to obscure the true destination and leverage potentially trusted domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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 https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/2ca1718c914f8c97fcd3e199b855a4d6/gugexelizutax.pdf In PDF document text
    • https://aluminiosarla.com/userfiles_arla/files/ragubegexoj.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607b046111380---xejalopibusikubupoviruloz.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/7924cd31fc2fb8fcaf837ce7ec52254d/59141054124.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/e6727a4d2c7bde05a8874c213571b0be/mixafepuj.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abb4f89bea0---13228871148.pdfIn PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/lawanoje.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/7b3520988ca10538ade20b2baeb107f3/refopunoko.pdfIn PDF document text
    • https://atamergranit.com/userfiles/file/vofijaberutiw.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/56700832998.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbd121ca64---26587544121.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/89407286890.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160968a2ec98bc---ralukiwija.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/gomefutuzeku.pdfIn PDF document text
    • https://pensiuneavlasin.ro/wp-content/plugins/super-forms/uploads/php/files/dvr45buhsuso6vu8lpk0q3t99e/50535232558.pdfIn PDF document text
    • http://bwc.lt/i/92892473604.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160800499568a4---judiwodimu.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/f438da00735fa85e73b976481d3edd45/89787969194.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/vawuzunifofidamuxipef.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a960944d08f---70091210204.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/17ec33974d5779635275b1a07319f3f7/warasipifudelitepekagajos.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160712e4c4ef3e---44489425226.pdfIn PDF document text
    • http://chieusangducphat.com/uploads/userfiles/file/kotikakizavolit.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/nipebirumuzegike.pdfIn PDF document text
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/7d9764ad5d746b20602bb600e2f58bdf/tufusezawiw.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/luregixid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=complete+the+sentences+using+the+correct+form+of+the+present+tensePDF 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_off0000ed07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED07 10896 bytes
SHA-256: 02310d760ccee547543a4ccc37b01fa9ff7ee24dc4b50f41035178ca6756bd2a
font_01_sfnt_off0001060c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1060C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1E 17740 bytes
SHA-256: 9b3ce23f64dad53be84c91b565896caf824f36cdb57e5bfacd019d824e43cea2