Malicious PDF — malware analysis report

Static analysis result for SHA-256 a438c533a5d6b828…

MALICIOUS

PDF

91.0 KB Created: 2021-08-16 11:12:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 9a6309b4518f72a0cda98e49d81df6b5 SHA-1: db5b365c1ae10535be52848dbe6a9fb713d22f7f SHA-256: a438c533a5d6b8289fafe572b2c8d7f7c9d4ac899ed4a98d7458915a8a4f6940
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that form a link farm, with many pointing to compromised WordPress sites or disposable hosting. The primary purpose appears to be directing users to malicious content or phishing pages through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://laborke.ru/uplcv?utm_term=what+is+othello%27s+flaw+as+a+tragic+hero PDF link annotation
    • https://club-sports.net/uploads/products/files/59553009394.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/43118362987.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/4d8e124140a2467466800c97a81b2f01/57522271307.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/rih38j2nhce5ouka887ujvcj89/zulizupuverudofulijib.pdfIn PDF document text
    • http://bogelaipigeon.com/upload/file/60505122862.pdfIn PDF document text
    • http://dgjst.com/upfile/file/9130050300.pdfIn PDF document text
    • https://penal-garazh.ru/files/58910654930.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/39520386847.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607090814905d---raxobipimopomozupi.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1606f05803c6b9---wowafidinapugan.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/df161625700cd318aae613ace642ce62/rijelapalapoxoveramur.pdfIn PDF document text
    • http://nyitotthaz.hu/userfiles/files/30192062197.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160720f36e6e53---82836262339.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608224340102b---gifafabexizenititobot.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/24839899559.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16096e6c46980a---40231170972.pdfIn PDF document text
    • http://kibunajcc.com/ckfinder/userfiles/files/95214307070.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff83ca07a3---bovodamut.pdfIn PDF document text
    • https://balarampurblock.in/ckfinder/userfiles/files/suruwasidopefizopanebad.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/i1ok1gq5a7hvivin0uhrsmr1o0/nafaxewuj.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/6794accca7f70f1ea615f7ce77258284/divizetivobipuvosezufejiz.pdfIn PDF document text
    • http://anm-av.de/uploads/files/didun.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/61831670988.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3a29128c0---pefuxi.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_off0000f25e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF25E 10624 bytes
SHA-256: 202450e8da3d1418e1c321c37a6a1e49056372848c0dcce06e1568abe7998a1d
font_01_sfnt_off00010af2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF2 29464 bytes
SHA-256: 092e63cd91e20538ad81d46d4e09108b32096cad1894b1565f5a9dab103d8fd8
font_02_sfnt_off0001451c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1451C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1