Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f95083e7afb97f…

MALICIOUS

PDF

81.8 KB Created: 2021-07-04 10:31:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6cb3e2ddb52fab8577030fa0f3e7b5d3 SHA-1: c9ab4e7d204b33be3eb8950884b3fb2f0719772d SHA-256: 28f95083e7afb97fa706e77d3b5b16eb8780e04071910ec78c263defc9e7fc30
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 hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7832

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://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/681ec950e3c5638d7e4dab5bf686a3c0/xexupisekadaba.pdf In PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/65ba23fe3e75149150e2ade7734f1df3/sepuwik.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a21feaf3b94---paniwuwivus.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1609841625f974---lifegaz.pdfIn PDF document text
    • http://vzwsportenmuziek.com/content_docs/82671716533.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf02447bc9e---49919004914.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/gobuxuva.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/djdvapi2jk9upqpui167rbuibd/zatogu.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/ie66jcm0t9d15oq5poho9b0mli/34892060564.pdfIn PDF document text
    • http://lpkgoodframeupvc.com/userfiles/files/luxuxemiwitifoxipemivofe.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/sigimizik.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb88a4160e4---givibaruninipegideziji.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16080783d90a34---jemajuxatarinuraz.pdfIn PDF document text
    • https://digireg.nu/upload/2291851596.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/43q2c9l6sgpkctlmk34pcdp2ci/tusomu.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/dc418d1311eb4d4d3490935e4b77ef9b/sevorofebig.pdfIn PDF document text
    • http://bungefamily.com/clients/5233/File/8797767189.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/81219afd1644c85dc2e283edd439e246/sojuko.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/2160691a2b4ddce04f2b9a547b69724d/ninidodilodosi.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1d85741fd---vafalafegebaxodupizagaja.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202105112230.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c01078b9c---kowonosirurezoguzonobiw.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/daktau7p4p9s70qv1694ook2m5/84978477738.pdfIn PDF document text
    • http://bestbuyfromindia.com/userfiles/file/zuguw.pdfIn PDF document text
    • https://teenvolunteerhouston.org/wp-content/plugins/super-forms/uploads/php/files/d827d8917f7cb97220876f3ac75cc340/kanemiwexatifuboret.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=brow+shape+for+square+facePDF link annotation
    • 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_off0000e44a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE44A 10620 bytes
SHA-256: f0cb411cac04c815d7efa2a39f1cc0a6f039961801f5888da4ca077508b0d293
font_01_sfnt_off0000fcd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCD8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114EA 16928 bytes
SHA-256: e6b85b94fadcea4f206242a630956746d11cbf8da7e33023899330b2baefef36