Malicious PDF — malware analysis report

Static analysis result for SHA-256 888d3cfdfc864cc8…

MALICIOUS

PDF

88.5 KB Created: 2021-08-11 05:05:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f0d4c82ade20af2742f3fbd6773f3f12 SHA-1: 4016e77b0fbbbc6d827fe151d5df2fa451d2afcf SHA-256: 888d3cfdfc864cc84d9025b6c97084ce23d7593d3eb960a5450a2442ee0a322a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ClamAV and ML classifiers. It contains a link farm pointing to multiple compromised websites, likely intended to trick users into downloading further malicious content. The presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e30f665809---52936704870.pdf In PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/87264003866.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/871baaa1731e248f20d912c57373589b/50055326783.pdfIn PDF document text
    • http://pngroup.pl/ckfinder/userfiles/files/mewoz.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/168d4107ad0cfab4366cbb61ca34ee71/64595060145.pdfIn PDF document text
    • http://vakantie-noordlimburg.nl/ckfinder/userfiles/files/40136718892.pdfIn PDF document text
    • https://zebcom.in/userfiles/file/40658489155.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/vavosuki.pdfIn PDF document text
    • http://quangcaosms.org/media/ftp/file/4954857455.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/lopewukewaxazefenemazuzi.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b00094765ef---demos.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/86a0e20cc5445d9b970b3d502a9044e6/badixel.pdfIn PDF document text
    • http://studiopassarotti.it/userfiles/files/vofoxozenosotebad.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/u7ga5r7o93lkdoeke71ipu3hdi/nepagaxosadutanevazu.pdfIn PDF document text
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/mojakemi.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160c2b9be03c39---ledizemo.pdfIn PDF document text
    • http://malverne69.com/clients/a/a7/a743c233813d1a1dbf5c38c484d85cdc/File/15117680720.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gutipisulitogepumuxu.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/nakuzesinafamodadekax.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/rlvlaubpdosdkcldlhfgipeucj/1221404067.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/59971472809.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/3ca870960699707f02f415bd1d7c4616/korewokamamumere.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=biolog%C3%ADa+molecular+de+la+c%C3%A9lula+alberts+6+edici%C3%B3n+pdf+descargarPDF 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_off0000ed1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED1C 11780 bytes
SHA-256: 4324ccc21b9149e8503bf451a9f142b2ad20bfcf00e767e2f777cb42f60ae166
font_01_sfnt_off00010836.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10836 18408 bytes
SHA-256: f9b9ae9c17f66e150f656f18ea15c5ea77620aa1b81637aff374f0f4f832a5a9
font_02_sfnt_off000137b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1