Malicious PDF — malware analysis report

Static analysis result for SHA-256 79c6820c4d3cb809…

MALICIOUS

PDF

72.4 KB Created: 2021-10-04 04:21:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 377e0fb284e7ced116ff3551b6e6300f SHA-1: 1bfb48030c3551e0b0737509f6259b8075b6b0f5 SHA-256: 79c6820c4d3cb8093f770671498d0cd69b248e99d3dd42efc225671674ce878e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, directing users to various domains. Heuristics indicate these links are intended to exploit SEO tactics and point to compromised CMS uploads, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly support a malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://cructi.ru/uplcv?utm_term=how+to+draw+elsa+from+frozen+2 PDF link annotation
    • http://affectif.ro/data/Image/file/ponixuxiromaguvukobadiv.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/20341507852.pdfIn PDF document text
    • https://svezadjecu.me/userfiles/file/fuwelunafifakorated.pdfIn PDF document text
    • http://daiquangsico.com/img_duhoc/files/viremepali.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/59146563856.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/sazupat.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b94131c21a---28717095666.pdfIn PDF document text
    • http://cherryontop.pl/upload/fotki/file/mepuxolegin.pdfIn PDF document text
    • https://aiwcecckolkata.org/FCKeditor/file/54461774171.pdfIn PDF document text
    • http://balbu.hu/uploads/news/file/visosepi.pdfIn PDF document text
    • https://5uempat.com/contents/files/majurirumiluzadogevator.pdfIn PDF document text
    • http://zhouzhuanx.com/v15/Upload/file/2021925444543973.pdfIn PDF document text
    • https://rm-parketi.si/uploads/papoxomejiruta.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1614e5e34dcba0---vijixivisozosevekovefa.pdfIn PDF document text
    • http://citlak.de/admin/UserFiles/file/fitasubobonadofirut.pdfIn PDF document text
    • https://tonerihned.cz/userfiles/file/numarigakufenemapim.pdfIn PDF document text
    • http://iqlacpro.vn/emotive/upload/files/73723123441.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149e533a3ce8---70700297435.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/relatedasenogu.pdfIn PDF document text
    • https://tranthachcaodanang.com/uploads/image/files/sufamelesoxigapokegoz.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/livaxetomo.pdfIn PDF document text
    • http://anninh247.info/upload/files/8930844750.pdfIn PDF document text
    • http://commsoft.nu/demo/ktb/wsmbilder/files/15467628742.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/gekomarijawuruzofiji.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_off0000b600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB600 10680 bytes
SHA-256: b2dea1d6dca1c83a259ed1d3cb24b78f2200f92fd155b494a0c2f66fd9d2e4dc
font_01_sfnt_off0000ce98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE98 17484 bytes
SHA-256: 57b248e2f0cbb2607a806967caba8169b14c87ac413db1ac1adbcfc8ce9ab66a
font_02_sfnt_off0000fb94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1