Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c6ff5f3f5b3cfe5…

MALICIOUS

PDF

86.2 KB Created: 2021-08-17 09:03:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1f57e7d9b56282e0edf4e6de6c375da2 SHA-1: e3c3a5787c50d144481a4cf87e46c33f87dea47d SHA-256: 8c6ff5f3f5b3cfe5ebedfa5ba39749eb1f4c26c353ccc6953e3f12d5610ca4a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file contains numerous links to external websites, many of which appear to be hosted on compromised WordPress installations or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=preposi%C3%A7%C3%A3o+exercicios+7o+ano+com+gabarito
    • https://roeveragri.ac.in/wp-content/plugins/super-forms/uploads/php/files/eb5db8bf035ecbb8878bba6a4f3feca0/kefapazemikojonexu.pdf
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/444f0c11997aca9392365b3075ad5f9d/62323805223.pdf
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/83cefa02fb50809cdd845320eb4006fb/78509360506.pdf
    • https://on-call-anatomist.org/ckfinder/userfiles/files/narapilifupugoworuvota.pdf
    • http://creaorganization.com/depo/sayfaresim/file/pebozokokemomapepo.pdf
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f836ff77ac0---81107602181.pdf
    • http://bajcsidavidfoto.com/_user/file/mopixu.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/849643e4e31ce4574875ac73317617f5/sofezilofepalati.pdf
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e344906ee15---81124675883.pdf
    • http://deborahbrown.us/clients/860103/File/89586901991.pdf
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/towuretudetefira.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c0c8a15d58a---domujusuzumumet.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/m05bli5pmiqn2nkm6ljcj7i5l5/83349201732.pdf
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611b170238c69---kexolugowofowudumezowi.pdf
    • https://alarouba.com/ckfinder/userfiles/files/zolekubepetabakag.pdf
    • http://valleypainclinic.org/userfiles/file/rogezu.pdf
    • http://elitvorota.ru/f/file/90130105181.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/r4hdso4kd2e2vproh16o1gerf3/42349511911.pdf
    • https://protradingindia.net/userfiles/file/15918387806.pdf
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ccd511c6bc0---kejomimu.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac407cf63f---57757787563.pdf
    • https://burgas-remonti.com/userfiles/file/danugaduruvi.pdf
    • https://habibitours.org/ckfinder/userfiles/files/zunef.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bdd6f0130f1---18350506538.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9f767c2dc---molemigeluduguk.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e613.bin
a08f430581c9798a4e0186398588ea14f6f8645c6766c601dd16b5c5d8925820
pdf-font-stream PDF embedded font (sfnt) at offset 0xE613 19152 bytes
font_01_sfnt_off00011537.bin
c6b185e26ce5c34a8bf1ada7d854b1a8fdc2e906a0f63941173fbfd65360bd4b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11537 11428 bytes
font_02_sfnt_off00012f5d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F5D 16792 bytes