Malicious PDF — malware analysis report

Static analysis result for SHA-256 f88c6592eefd15ed…

MALICIOUS

PDF

88.4 KB Created: 2021-09-17 20:19:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7bad5c0859d4edd395fe888da2dc843a SHA-1: 8b7237cb3613148844b20bef19de6d3fb9806b91 SHA-256: f88c6592eefd15edae795a4895db173b5db231552ff1a1dd00b9de406413f1e0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple domains, some of which are hosted on compromised or disposable infrastructure, suggesting a phishing or malware distribution scheme. The PDF structure and embedded URLs are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=invention+of+wings+pdf PDF link annotation
    • http://hwayinn.com/image/files/20210913_202749.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/zuniluwuwudurelekodag.pdfIn PDF document text
    • http://casinodanmarkjackpot.dk/userfiles/file/63651223240.pdfIn PDF document text
    • https://cvssteelex.com/ckfinder/userfiles/files/widapupomizaxiw.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395400efa54---88160795501.pdfIn PDF document text
    • http://gabortech.com/admin/file/kafuponupafolif.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/pujun.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613add8fc427f---zofivikegut.pdfIn PDF document text
    • http://world-green-hope.com/uploads/files/vusaremulevizugaro.pdfIn PDF document text
    • http://atomleasing.ru/media/File/56875966108.pdfIn PDF document text
    • http://showdoimovel.com/files/files/kuxojupen.pdfIn PDF document text
    • https://tylbm.com/Upload/ckeditor/files/24829575623.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fee6251426---571571509.pdfIn PDF document text
    • http://reafamily.lt/ckfinder/userfiles/files/kupudabenilugogubepi.pdfIn PDF document text
    • http://manchetenewsms.com.br/ckfinder/userfiles/files/3872473501.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16132594e93a22---wofexipasideveku.pdfIn PDF document text
    • http://benetworkingpro.com/ckfinder/userfiles/files/telanagegubiteru.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161302193e991a---xatateriwinisimadufe.pdfIn PDF document text
    • https://www.lipca.com/ckfinder/userfiles/files/fuseraloluriruzi.pdfIn PDF document text
    • https://www.meditech.cz/ckfinder/userfiles/files/tizobazuvi.pdfIn PDF document text
    • https://flomogroup.com/upload/files/39413967994.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/95477198796.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/tukozifimeripewan.pdfIn PDF document text
    • http://nawooelcs.com/upload/userfiles/2021/09/files/210913154637.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_off0000f333.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF333 18968 bytes
SHA-256: 7f792a2e874ab19062b6fc760c9be2b417eaceeb687e61b4adc04865761e928e
font_01_sfnt_off0001242b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1242B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013c42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C42 10468 bytes
SHA-256: bd49b2571e12b1923b79b061d2afc37be851f0beccd4f121889f75e2ad039d76