Malicious PDF — malware analysis report

Static analysis result for SHA-256 71abd151fb8d9ad7…

MALICIOUS

PDF

85.8 KB Created: 2021-08-20 15:53:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 0f984b0e330e1c1ba43bfd152b2a1778 SHA-1: bc11c779811a62e007d1686c11cdd74be11444bc SHA-256: 71abd151fb8d9ad75c21ce1bade066740906dc7a1c6fbda6d05e551373bf5268
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many pointing to compromised CMS upload storage, indicating a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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.
  • 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://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a304f7cce64---wufulurulutixeru.pdf In PDF document text
    • http://amon-syotengai.com/userfiles/file/33583232779.pdfIn PDF document text
    • https://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/solexugigib.pdfIn PDF document text
    • http://chenruichem.com/upload/files/nivoxalaboki.pdfIn PDF document text
    • http://williamshudson.org/clients/3/35/35bf74ce48b5c120232fd40fb4fe3e45/File/fesuviledufoxas.pdfIn PDF document text
    • http://hopkinshigh1988.com/clients/75739/File/42608645709.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/83cdc5b33c39056ec3f10274b7ad0e51/pogekilo.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e9d628265---durodedenulewutilu.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/muzuteb.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c34ac0747d9f36954ff9a3788314e62f/nututamewojogoda.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085770d4101a---22850942969.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/56f7138f1f38f1b4c0d3ee574740b89e/zemadofomidimenito.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/71fu9tcmn0dion4kvht229isl5/fozebi.pdfIn PDF document text
    • https://lienlacanien.com/img_pages/file/7795869663.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210731045204.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ddaf3b977---wobisu.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/23087395166.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/47a52c61d766399bed6d93e8817620a2/golulijevudigemezuju.pdfIn PDF document text
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tejotetijerufi.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/nukimano.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/baxinimefisowa.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/dkvo35k1k3ja7eo9c72jhrrlbi/xadepedikolubibuxoma.pdfIn PDF document text
    • http://epmachine.ru/d/files/mepevodigigoxozuparik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=amd+phenom+ii+n640+dual-core+processor+drivers+downloadPDF 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_off0000ea49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA49 11316 bytes
SHA-256: db10c700b1ee4b4f52d1c75d8ff7e68f7481fcd9048389a2cab6e0461c0a2306
font_01_sfnt_off000104c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C3 17048 bytes
SHA-256: b5ac50012a7750f3195fd60d85513e37e757c9a19689972977d1eda7eb84adcb
font_02_sfnt_off0001311d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1311D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1