Malicious PDF — malware analysis report

Static analysis result for SHA-256 b920f49d41e7c0d8…

MALICIOUS

PDF

75.4 KB Created: 2021-09-06 18:59:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5e77681a05ebb72bbf17cf038b2001fc SHA-1: 35da9b4cce601f60ef3949be3bee87f096f79bc0 SHA-256: b920f49d41e7c0d8c35cf1580ce7672aa6c4421e8ddf5bd2fbbc1a52140bef40
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to various websites, many of which appear to be compromised CMS upload directories. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for link farms, suggesting an attempt to manipulate search engine results or host malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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=html+to+pdf+api+php PDF link annotation
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071e8956f265---kalotefejiminamusonova.pdfIn PDF document text
    • http://hopkins1983.com/clients/861771/File/tigugerosevimem.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/74982326095.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/xerizerobupufinefab.pdfIn PDF document text
    • http://emotionpicturesfestival.gr/userfiles/file/robuw.pdfIn PDF document text
    • https://subarini.ro/mm/file/jelasazetenisawefi.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/29bd87fb51ec647a65a823c21fb175c0/netumixilexinedowebapeb.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210822072352.pdfIn PDF document text
    • http://traviet36.com/upload/files/subarubob.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/nunejiku.pdfIn PDF document text
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075a67d043b5---likinuzuwufopevu.pdfIn PDF document text
    • http://andrewsexes.org/clients/867461/File/gejorijevekoxobolomab.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160852d247a6c3---15284508058.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5f6342c56---volawebuvojizovuwox.pdfIn PDF document text
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085543fa8e77---wavati.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/visedunepefiravi.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133037be10ae---8316947284.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/38169477075.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/9c23f8f7c0f761179c23a9cd866ae6ea/84118040767.pdfIn PDF document text
    • https://shidoremicrosys.com/media/dajilori.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/0aa12120e3d0c7c6b6a6dd825f4aea7b/59737449965.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/worugonupepijutudurira.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_off0000c274.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC274 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA8B 10248 bytes
SHA-256: efa5a6787e5380fcc21515bcc8955a8b6ca4d5303bfb68376d122f062a3467e4
font_02_sfnt_off0000f171.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF171 17948 bytes
SHA-256: 1315884801d828605b0024c5f7e46271dabd13aa2da4454d3ebc306601f8d188