Malicious PDF — malware analysis report

Static analysis result for SHA-256 865c94bdf226d708…

MALICIOUS

PDF

85.7 KB Created: 2021-07-06 08:06:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 4d41fec4f21675eb027b0a5f66522c49 SHA-1: 88e1b5c82d34c10c580df43b97aed2432be8bea6 SHA-256: 865c94bdf226d708e1e5a00199e30cd62f7deabc53f7cb5edcaedee450d24f42
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm structure. The embedded JavaScript likely executes malicious code, and the link farm points to multiple distinct hosts, many of which appear to be compromised WordPress sites used for hosting PDF files. This suggests the PDF is designed to lure users to these sites, potentially for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160afab1f6f1bf---kijibovifapoxodivunogejov.pdf In PDF document text
    • http://digemnd.com/UserFiles/file/65311820398.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/mijivinolexuviruvajatep.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/6e21b80139cbfb9f9944d1c994c49e71/13065888408.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d2b2d08d97---342293361.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/roferukegunifefu.pdfIn PDF document text
    • http://iphysiology.ru/upload/papibo.pdfIn PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/xokigu.pdfIn PDF document text
    • https://daleel.global/wp-content/plugins/super-forms/uploads/php/files/a5b2tq5io3ku360f98a75u3b69/4380938739.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160dfa32bd57e5---kedutepobilenowawugugerel.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/86340208517.pdfIn PDF document text
    • https://gofropack.com/wp-content/plugins/super-forms/uploads/php/files/eebcbc7c69ead771b16da6d25ac79f08/44036828524.pdfIn PDF document text
    • http://gunjanjain.com/app/webroot/js/uploads/files/fubodufovagosomoviluxi.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160d466154ab3e---zazijewijofazukesodaf.pdfIn PDF document text
    • http://porpora.info/imagenes/imagenes_contenidos///tepogov.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/50094973305.pdfIn PDF document text
    • https://www.adilaltinsoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073c43aa246d---55326159140.pdfIn PDF document text
    • http://heizler.hu/files/file/84049055114.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0ec419d20---9474037973.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b991c3c2d87---94881062813.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16070e3b67a21b---lunibosixevipas.pdfIn PDF document text
    • https://newtop-eg.com/userfiles/file/kuribajutokazokavuwaxovi.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160708ad9a03d3---94382963513.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=demi+and+kristianPDF 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_off0000ed8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED8B 10336 bytes
SHA-256: 54b09748ac8991c11a81543666041921707c61ffe83c18ce465d91564973e301
font_01_sfnt_off000104d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104D6 17392 bytes
SHA-256: 6bc8c975f073bbf8f6c7ffb79f18e7bfa6e12c6b3d72140a667b241550e3f292
font_02_sfnt_off000131fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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