Malicious PDF — malware analysis report

Static analysis result for SHA-256 28a06fabcd567903…

MALICIOUS

PDF

88.3 KB Created: 2021-09-07 11:10:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 12bcb84088614ebfed5def20d6273dfe SHA-1: c7b254b0c063074c329891852bbe9082b4f56487 SHA-256: 28a06fabcd567903c270cfb311960011c6f163b512ed24b8f127b01b16779194
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 other PDF files hosted on potentially compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution through a link farm. The presence of multiple PDF link farm heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/fc0676707ba0a259ffc8c6d53a82c3a9/puwurux.pdf In PDF document text
    • http://vtdsbinhthuan.vn/public/uploads/userfiles/file/2880518087.pdfIn PDF document text
    • http://classicalgardenfountains.com/uplds/file/13140327302.pdfIn PDF document text
    • https://addsfly.com/userfiles/file/siwiwu.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/34794718880.pdfIn PDF document text
    • https://kaptenhoki.info/contents//files/vizunigo.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/piberepotare.pdfIn PDF document text
    • http://scsytech.com/upload/files/warudoxufekodamelirenusuv.pdfIn PDF document text
    • https://kleinimmobiliere.lu/userfiles/files/71329904152.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab09e42716a---25978971781.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a24ee4293---74520792827.pdfIn PDF document text
    • http://railwaysrailroads.com/upload_files/files/lorifup.pdfIn PDF document text
    • https://sts-cct.com/app/webroot/userfiles/files/pixixe.pdfIn PDF document text
    • http://cokhilegia.com/upload/files/1702163095.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1606cede51fc87---37002044542.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/92816124502.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f59e8dc257---lirabowazuxinafetegapep.pdfIn PDF document text
    • http://pk.mo/userfiles/file/87857873518.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/49e9d603c6c38dcfb7f29e0a8dd7251b/6204441991.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160911d5fc3d17---38107892270.pdfIn PDF document text
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/8678d37c3bc9c8e14db82011ab3d8888/kudolux.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210807075031_tgvagk.pdfIn PDF document text
    • http://xn----8sbxab3abskk3a2j.xn--p1ai/media/file/duwofejijujikiwobifolaxu.pdfIn PDF document text
    • http://letdentalab.com/img/files/zigogedugubobipuripow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=school+management+system+project+in+vb+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_off0000f3d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D5 17028 bytes
SHA-256: fd760adac41aaa24138108842b9b56f17d6a6e899b06117e60c0b7a7fdb1a5cd
font_01_sfnt_off0001200c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1200C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013823.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13823 11592 bytes
SHA-256: 0a7a9ce49ddc0d1fdedaec03968976457ae4f05cadff19e5f9f29b78b9655dc1