Malicious PDF — malware analysis report

Static analysis result for SHA-256 5356142b4c5e380d…

MALICIOUS

PDF

62.5 KB Created: 2021-09-27 20:46:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a0a07811515b05809319cd586e584275 SHA-1: 9bd162fc4937ba3c7b66b01470a7a9de9931a98e SHA-256: 5356142b4c5e380d0337456ccb33f72fd1da15cf9988fa9da50a6130c9dee29b
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content. The presence of external URI heuristics and the PDF_SEO_DISPOSABLE_LINK_FARM rule indicate a deliberate effort to create a deceptive link structure. No scripts were extracted, but the overall pattern suggests a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5156

Heuristics 5

  • 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
  • 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=phrasal+verbs+pdf+book PDF link annotation
    • http://rencontres-icare.org/userfiles/file/43331876668.pdfIn PDF document text
    • https://konyaalotaksi.com/userfiles/file/82184335267.pdfIn PDF document text
    • https://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/40588134300.pdfIn PDF document text
    • https://gujaratisamajparis.org/upload/files/fajenumoxukede.pdfIn PDF document text
    • http://royalrep.com/userfiles/files/pofepowulazakazariwolev.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/tv8l51g1dkqjuq69fjbp0cibvg/16340069711.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/9377143072.pdfIn PDF document text
    • https://incense888.com/uploads/files/202109161910253919.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408865b52f8---59483223409.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16130111d87a28---62734122226.pdfIn PDF document text
    • http://iucecb.com/files/file/23421550981.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/44438009319.pdfIn PDF document text
    • http://kvarkeno56.ru/userfiles/file/bijopononuwenumobipofoka.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaba6dbb6c---gomujulosujog.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614b67b733315---74114505134.pdfIn PDF document text
    • http://3t-t.com/User_File/UpFile/file/20210902063345_anVib3Nhem9waQ==.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/9hh8giv45ei14cd6o7sjsq15ke/93956057365.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/b3cce8a1a76f81818667126ddc2c9177/dikobutekige.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/vikofevedujo.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/27807713862.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efe9112f44---91086749430.pdfIn PDF document text
    • http://cascad-trans.ru/files/legiseb.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16322064375354.pdfIn PDF document text
    • http://ghettaetamionarchitetti.it/userfiles/files/jazoz.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/30934614510.pdfIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b4e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCF5 16120 bytes
SHA-256: 05d9bf25c0237b7d58eb8eba7bc54dad1d675b87e639b5d0dbca99c3b7e8249e