Malicious PDF — malware analysis report

Static analysis result for SHA-256 b728ca090167d837…

MALICIOUS

PDF

75.1 KB Created: 2021-10-08 03:23:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 265608997f670efb6137102f468a0930 SHA-1: a3d7ceddb59117f3ee4735fbc1688f8904e6da6f SHA-256: b728ca090167d837a1d3c23c1779a9c5c62db13192490ea82d6e858b6e70e284
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting vulnerabilities or redirecting users to malicious sites. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM and the numerous extracted URLs, many pointing to suspicious domains, indicate a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ombs.ru/uploads/files/wugubomejaruf.pdf In PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/12462654865.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/jivalavorogobu.pdfIn PDF document text
    • http://jiducn.com/userfiles/aa/file///jilifawupuravidixodulut.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/79096954311.pdfIn PDF document text
    • https://serka.com/serka/upload/files/zuzatapifafunoj.pdfIn PDF document text
    • http://hong-tour.com/FileData/ckfinder/files/20210922_158AD0064EC30CBB.pdfIn PDF document text
    • http://klgd.spokoino.ru/i/upload/files/62613520666.pdfIn PDF document text
    • http://licausi.it/userfiles/files/lajovijabawunut.pdfIn PDF document text
    • http://etpatatietpatata.com/userfiles/files/98059772436.pdfIn PDF document text
    • https://coopinproject.eu/ckfinder/userfiles/files/4829950838.pdfIn PDF document text
    • http://fuerst-architects.com/uploads/file/paruzegopoduvowokirabelin.pdfIn PDF document text
    • https://morethancars.eu/uploads/edytor/file/20231433800.pdfIn PDF document text
    • http://springgalleryng.com/Images_upload/files/74427553349.pdfIn PDF document text
    • http://www2.grupoksl.com.br/js/ckfinder/userfiles/files/29027604592.pdfIn PDF document text
    • http://vendsol.com/userfiles/file/58388565988.pdfIn PDF document text
    • http://www.pilatesyoga.hr/files/files/93029137418.pdfIn PDF document text
    • http://bjsddesign.com/filespath/files/20211008063059.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/nujukenevid.pdfIn PDF document text
    • http://massimosusto.eu/userfiles/files/88083230472.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/9493252944.pdfIn PDF document text
    • https://heritran.vn/uploads/news_file/7279709627.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/1843849661.pdfIn PDF document text
    • http://vaonhaphatphap.com/images/uploads/files/madokijodagibudumoxokub.pdfIn PDF document text
    • https://www.multilandtours.com/assets/ckfinder/userfiles/files/28892717408.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161407fdc85592---gozasarazago.pdfIn PDF document text
    • https://emailing-online.fr/uploads/userfiles/file/7623700491.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=crypt12+file+converter+to+pdf+onlinePDF 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_off0000c264.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC264 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA7B 10668 bytes
SHA-256: b561b3ef18be44dba39f7bf101735ef7317097f205b9d22c4faced71cb44e65e
font_02_sfnt_off0000f323.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF323 16572 bytes
SHA-256: 7944a2527eab68004f230ebec648a02b78531d1cdf49c0aabb59d61925ef99b2