Malicious PDF — malware analysis report

Static analysis result for SHA-256 8dab74403553148e…

MALICIOUS

PDF

80.6 KB Created: 2021-09-10 18:49:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c7b2d12f59e21bfd35a881198c5c7845 SHA-1: 2a872ab6be33676bdef71435f32c7931bdbf35fa SHA-256: 8dab74403553148ef89fb540eeb85f66d98e79862b849338f1b728179da27f9b
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files, many hosted on compromised CMS uploads or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated, preventing analysis of specific content, but the heuristic firings clearly point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://beautydent.hu/editor_up/68277266827.pdf In PDF document text
    • http://rkmaster.ru/uploads/files/menoze.pdfIn PDF document text
    • http://9275522-travel.com/userfiles/file/gamobarikuxivoxow.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/dirobizamuwub.pdfIn PDF document text
    • http://progetec.org/userfiles/files/87978223978.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210905_15F5C47DF9C525AA.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/babonagajorodo.pdfIn PDF document text
    • https://ceccardolj.ro/userfiles/file/68869665363.pdfIn PDF document text
    • http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/77009860634.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/vuvefewoxajufogafazuragop.pdfIn PDF document text
    • http://atdawnwelift.com/userfiles/file/45920370966.pdfIn PDF document text
    • https://doctornhospital.com/banglanews24/editorsfiles/files/geserisinus.pdfIn PDF document text
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/nakarovatenalovuseviwigi.pdfIn PDF document text
    • http://fecirturizm.com/resimler/files/riwowizibapuluwefexog.pdfIn PDF document text
    • http://ranch.pl/files/file/66719155912.pdfIn PDF document text
    • https://delphin-bau.com/ckfinder/upload/files/xeserakekabuguzimuvuzo.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/tuvife.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/6dc8caf7764209dc2fa952cf5d818ce9/vepakotijerev.pdfIn PDF document text
    • http://brickchamber.com/ckfinder/userfiles/files/mikotew.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a96656ece4---wajeluxigabigugatubivu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133525dacd59---75970413225.pdfIn PDF document text
    • http://maychebiengoduykhuong.com/media/ftp/file/16870871791.pdfIn PDF document text
    • http://kraemer-duennebacke.de/files/file/63590047894.pdfIn PDF document text
    • http://exms.fr/sites/default/files/file/23227201571.pdfIn PDF document text
    • http://nct-vn.com/userfiles/file/13739026579.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=how+to+win+friends+and+influence+people+book+pdfPDF 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_off0000d5b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5B6 11024 bytes
SHA-256: d2271fdaf0d2fa6f60f14285f502fe17cf148fcd3032b5c4cb5900436432283c
font_01_sfnt_off0000ef3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3A 17352 bytes
SHA-256: 81340798037e48c6c5163bb360d09ed238e00aeb53470e2e3e4aa28073ee8965
font_02_sfnt_off00011c2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1