Malicious PDF — malware analysis report

Static analysis result for SHA-256 85f2122fca07e3a3…

MALICIOUS

PDF

73.2 KB Created: 2021-09-06 15:44:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 98f926d17d7dc05e993f436d56c6007c SHA-1: 0b49570ca884d07a641013e34c8990a41ddb4ddf SHA-256: 85f2122fca07e3a3e7aabc86bbf591020da1d3567f94cd436e315c8ebb56d5d6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing or malware distribution. The primary function appears to be redirecting users through a series of links to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/hnj21phgvgo9rqhb5stlfuluku/senituvuf.pdf In PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-7-8/20210708041958293519.pdfIn PDF document text
    • http://cestovni-postylka.eu/userfiles/file/nadonuvunotu.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb5fd90c07---33932203686.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/21205713464.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/60058858287.pdfIn PDF document text
    • http://somersetcountybar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30877930454.pdfIn PDF document text
    • http://itemclinicchina.com/ckupload/files/47217461399.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/95004725317.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d48f506c870---45305238638.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c28011b6eb7---kuwinubolamuligatopejokiw.pdfIn PDF document text
    • http://xn----7sbicwad4afgcgd5aph7d5e.xn--p1ai/ckfinder/userfiles/files/venegosumalotexi.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/fapuwowemikotariwavo.pdfIn PDF document text
    • http://kutyasturak.hu/images/files/fesaj.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/25026c3e55ee9818494a32cf58c5ae11/tiwilubiruvusikejoxamij.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/2507ff3d345e7f153a45d954b5a9b8c6/8423862690.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/68293029401.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/27801198542.pdfIn PDF document text
    • http://ansonseatery.com/uploads/files/ragutinanesabiwi.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/37942059527.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/purezajoberigasujedunipu.pdfIn PDF document text
    • http://jr.ac.th/ckfinder/userfiles/files/28243825836.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/92bebc2a086905b5fd356533bee7f1a2/11356651864.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b88a6431d4e---31267214077.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=plantronics+calisto+620+bluetooth+speakerphone+manualPDF 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_off0000b459.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB459 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6B 18040 bytes
SHA-256: 1262bba61c1ccaa069d81244d1af8f13d987c74cbc0c896764e546e475d75e5e
font_02_sfnt_off0000fa6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6B 11384 bytes
SHA-256: c6a7064d2623d29db5987bce4315b7b7cc97cd3c57e88bbe80601c2ab8401bae