Malicious PDF — malware analysis report

Static analysis result for SHA-256 845c0bf81c35cbe6…

MALICIOUS

PDF

85.0 KB Created: 2021-09-07 03:59:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f93b1f672148cfd93946c2cb8d72aa53 SHA-1: 0af2560f58b49f1f71d80d84781797dd6d5a7169 SHA-256: 845c0bf81c35cbe68d650edce34f03146981e24495effb3efbb36629f45ccdbd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to websites hosted on compromised content management systems or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The primary function appears to be a link farm designed to obscure the final destination and leverage potentially compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • 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.
  • 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://instalacje-elektryczne.net/ckfinder/userfiles/files/8954664560.pdf In PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607513955c6f8---nuxajewetomimegepipovot.pdfIn PDF document text
    • http://ducthanggroup.com/webroot/img/files/45430232337.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/pozuwefukubugidemije.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/dodaze.pdfIn PDF document text
    • http://ginzaoakland.com/uploads/files/xowokejitir.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/kaferova.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/sku0jpgrsqlf3j5d5c0k42r77n/37782802700.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/50649417449.pdfIn PDF document text
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/sjb4dfrfhr68j4cl0ih38cnrl7/54414582402.pdfIn PDF document text
    • http://dpsszczytno.pl/photo/file/88123449130.pdfIn PDF document text
    • https://trotusgrup.ro/ckfinder/userfiles/files/20974872276.pdfIn PDF document text
    • https://nada70.org/userfiles/file/pubexu.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612615870cca4---25223694625.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/pazopopovebuk.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df94c611eff---77532838449.pdfIn PDF document text
    • http://spc1962reunion.com/clients/c/c5/c535eb5d361035e84cedf1152ec4da8f/File/84572052024.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/gimozugux.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/40333158380.pdfIn PDF document text
    • http://emannsltd.com/userfiles/45510906616.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/77481131060.pdfIn PDF document text
    • http://premiumcsp.com/uploads/files/32043674508.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=conversation+topic+cards+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_off0000e61a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE61A 18492 bytes
SHA-256: 6f954c317d98ad7cb101a15fe4591d28e2f5ad24fb041a408c830eb57c2e41e9
font_01_sfnt_off0001162b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1162B 10664 bytes
SHA-256: a975a9d36c5d90ab8feb6055bb2130f8c1f8e88177b9154b906edaa7824ac6f7
font_02_sfnt_off00012ed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1