Malicious PDF — malware analysis report

Static analysis result for SHA-256 57ca66f1263e5355…

MALICIOUS

PDF

79.5 KB Created: 2021-09-18 17:09:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: efd639d417fc599b585eb5ae773a842b SHA-1: 0d3dc29a452d15501eacea723db7748c339077b4 SHA-256: 57ca66f1263e53559c02aa6fd98f646f776b2a383167cef12efec10e51d83b2a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple PDF-specific heuristics related to link farms and compromised CMS uploads reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 http://thevisionkharj.com/userfiles/files/95565321121.pdf In PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161341b3d9c800---69761938571.pdfIn PDF document text
    • http://sasnowosielski.com/ckfinder/userfiles/files/40099883406.pdfIn PDF document text
    • http://www.euro-fly.eu/userfiles/files/87864028689.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614252702d402---6190979899.pdfIn PDF document text
    • https://qnzar.com/files/96451389884.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/73778596655.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/vulimuvawobekibuzokodiv.pdfIn PDF document text
    • https://4wheelchile.cl/admin/uploads/file/77105208621.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1613782654b48f---8031275318.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/8998bdcc904f30b4ba4772fbc6a3d7d1/duwoderujodojojorisa.pdfIn PDF document text
    • http://www.egymast-segito.hu/uploaded/fck/file/95088173624.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/13723961159.pdfIn PDF document text
    • http://mycoapaisyl.com/webimages/files/43102523497.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/velelapuzemosex.pdfIn PDF document text
    • http://fs-select.com/images/blog/file/geratut.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/93053873547.pdfIn PDF document text
    • http://chanakol.com/ckfinder/userfiles/files/85630386623.pdfIn PDF document text
    • http://myapartment.de/web/editor/files/wujonadufomowavidixexiv.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16132f354d98a1---86445776699.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/zazuwimixebukupivipemog.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/96127305942.pdfIn PDF document text
    • http://pk.mo/userfiles/file/rugozawulidofifolikadejo.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/44514845326.pdfIn PDF document text
    • https://autopits-directo.migrupoq.com/ckfinder/userfiles/files/voxazapevurit.pdfIn PDF document text
    • http://volker-issmer.de/userfiles/file/54816528048.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=cricket+line+apk+downloadPDF 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_off0000d4e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E3 16888 bytes
SHA-256: 24f13f33601b3a96a9c116398dd9a1ac92add4e7dcc2cd931dd711e877b130f1
font_01_sfnt_off00010046.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10046 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001185d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1185D 10548 bytes
SHA-256: 25d20529382ab352e2c7f8ef00d20b727487a05295da28199a5c477ac71b0c54