Malicious PDF — malware analysis report

Static analysis result for SHA-256 718c843f85e9e818…

MALICIOUS

PDF

70.9 KB Created: 2021-09-20 06:31:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 98b2c3cc6d753cfd51ad7fab4a338a92 SHA-1: 00dfb1ec110f21a38b9bd174f92199e7041093be SHA-256: 718c843f85e9e81828684141b8ced538257f218cb010f057a312fa3e94553347
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings confirm the presence of external URI links and a link farm pattern. No scripts were extracted, but the overall structure suggests a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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://drafthe.ru/uplcv?utm_term=ppsspp+apk+for+pc PDF link annotation
    • https://imaggu.com/ci/userfiles/files/wufigijenemibupero.pdfIn PDF document text
    • http://www.premiumimport.nl/ckfinder/userfiles/files/zixezenabukalurukaj.pdfIn PDF document text
    • http://xiao-bao.com/uploadfiles/fckeditor/20210902/file/16305922345651.pdfIn PDF document text
    • http://tinavaron.com/ckfinder/userfiles/files/83478049503.pdfIn PDF document text
    • http://med-os.com/user_upload/file/witedoba.pdfIn PDF document text
    • http://hoangnamjsc.com/upload/files/pipojedezitu.pdfIn PDF document text
    • http://flashdisplay.net/UploadFiles/FCKeditor/20210910022629.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/patasixalukovi.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/dazepuk.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/93297577354.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/jibepisiwevasot.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/256069052.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161392d0aabb89---kajosoletogarenazinus.pdfIn PDF document text
    • http://meruzhankhachatryan.com/app/webroot/files/file/53033203908.pdfIn PDF document text
    • https://www.restaurant-latableedevercel.com/ckfinder/userfiles/files/13844150309.pdfIn PDF document text
    • http://domoticasociale.it/immaginiNewsletter/file/fewetenok.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/dawuwadod.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/87696230388.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/6ujhkhnrqareg0dp5t992t7gd5/segifagevewawivozewato.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a175b9f9ef---xiborikigujapog.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/59374666298.pdfIn PDF document text
    • http://ph-easycome.com/userfiles/file/lozedanazuborota.pdfIn PDF document text
    • 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_off0000b043.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB043 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c85a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC85A 10092 bytes
SHA-256: cbd9dd4cba0299c3e061ef466f54f27edc353c569548ee91014eb70b04805f8b
font_02_sfnt_off0000df0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0B 18516 bytes
SHA-256: 8f7e995538eab21ef7955e0dabcb83e70b194c450683f52e39e52833600a307a