Malicious PDF — malware analysis report

Static analysis result for SHA-256 b75cb51825ba7313…

MALICIOUS

PDF

79.9 KB Created: 2021-09-10 07:59:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e35d8109cfd2e34fac7b42ca990ffaf8 SHA-1: e72ab94cb4aabaa185fcf97093203cccf184ef2d SHA-256: b75cb51825ba7313b6b7ef10f15ad5bcae99abf718da071ebf16fcb1b0426117
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be disposable or compromised hosting. Heuristics indicate this is a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://oniceh.ru/uplcv?utm_term=registrare+telefonate+su+android PDF link annotation
    • http://apartmany.cucoriedka.sk/data/files/32967656051.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/95183954285.pdfIn PDF document text
    • https://8cj2aja7-8mxb.com/contents/files/vuwodosadubimiredafata.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/gafovegenirizokimidonorul.pdfIn PDF document text
    • http://joy05.com/_UploadFile/Images/file/ramenivufusapiwoxa.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/cde93b9b4e1c1a103c443b7236eecfa9/xedivuji.pdfIn PDF document text
    • http://murasakijr.com/uploads/files/wudovenexu.pdfIn PDF document text
    • https://h16hr15k-h19hr37urn.com/contents/files/webuvezukozobuxupaxekom.pdfIn PDF document text
    • http://kondicionery-fryazino.ru/upload_picture/file/zaxasetiwekojo.pdfIn PDF document text
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/nixomagofe.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161317299ddeb0---43096563436.pdfIn PDF document text
    • http://timandlor.com/userfiles/file/29818812385.pdfIn PDF document text
    • http://drivingtesttips.ie/fckeditor/userfiles/file/jiwizugavafezalesur.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134fd54747fc---71379064687.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/mapedu.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/47246599462.pdfIn PDF document text
    • http://phayaotechno.com/UserFiles/File/tubuvoxubenobufun.pdfIn PDF document text
    • https://tigaintan.com/contents/files/62539627926.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f553d0c597---79278945916.pdfIn PDF document text
    • http://baoveantam.org/upload/files/66850181513.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/434b7350aa6a3ba14ddcc3e1332acb54/42408868670.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/69539256888.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_off0000d57b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57B 10676 bytes
SHA-256: 8085186f55370ec126b1cc7a5016741e1f198b54f7aeb4dd4294197c98288410
font_01_sfnt_off0000edd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD9 17084 bytes
SHA-256: f55633a574635afc6337a2a838b4089afa7992af6eb8f7da0740782b5802d03f
font_02_sfnt_off00011a47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1