Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc8dac64b06357b4…

MALICIOUS

PDF

85.8 KB Created: 2021-09-15 15:19:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2cb7c2100408f11e19a192d458c17a5d SHA-1: 1b95ab896ab9e80b9ed8d33ed5ed51e1909bcb44 SHA-256: bc8dac64b06357b4c6d8551d8d501db753fbff0ddbc5e61fff04f6923d75b3c4
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, pointing to a campaign that leverages compromised web infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://archism.ru/uplcv?utm_term=minecraft+java+edition+free+play+online+no+download PDF link annotation
    • http://studioagm.it/userfiles/files/gadofejusekituvixipuluwur.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/5a5386a75803d8dcd310fded27e28e10/34804060352.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/88795003515.pdfIn PDF document text
    • http://businessnavigator.in/ckeditor/uploads/files/90074018393.pdfIn PDF document text
    • http://www.bash.cl/media/file/65968844741.pdfIn PDF document text
    • https://happycolaborativo.com/uploads/files/88860659417.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613d37222261f---10993714449.pdfIn PDF document text
    • https://stl-log.com/htdocs/cljr/data/files/24409345968.pdfIn PDF document text
    • https://ienter.bg/files/sedegibodipilap.pdfIn PDF document text
    • https://parkettworld.com/upload/files/48621049908.pdfIn PDF document text
    • http://www.centrosanmarco.eu/img/news/files/xotogif.pdfIn PDF document text
    • http://kjphotocon.org/data/userfiles/files/mezolirugakezetowakejota.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/fegisalagurapugitoraje.pdfIn PDF document text
    • http://galenbio.com/images/upload/file/dumoxepisirifevemu.pdfIn PDF document text
    • https://webhosting4.net/media/file/tubasufuwadaxigatatawon.pdfIn PDF document text
    • http://araulmor.tel-cor.com/images/library/file/17224711293.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea0027d161---87521950353.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/nebobenefox.pdfIn PDF document text
    • http://capri.lt/userfiles/files/regorobikukenaguvin.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/41590163355.pdfIn PDF document text
    • https://bodykneadstherapy.com.au/ckfinder/userfiles/files/74565206105.pdfIn PDF document text
    • http://portaldo.eu/contenuti/upload/file/29864192616.pdfIn PDF document text
    • http://hanleyresources.com/images/63737073492.pdfIn PDF document text
    • https://mpksieradz.pl/upload/file/mofalepotug.pdfIn PDF document text
    • http://investbuild.ru/var/upload/file/jodajiwemolefapo.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_off0000e6e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E9 18616 bytes
SHA-256: 2480587053eb5d4a746167dbf58d4e99953cb99359ca50a2392352172bbd0f1f
font_01_sfnt_off000117d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D0 10832 bytes
SHA-256: f6783370ece6962ac386f268a5c54f01533dfc928c6183083b8c4e8986a8075b
font_02_sfnt_off000130f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1