Malicious PDF — malware analysis report

Static analysis result for SHA-256 31429be05084ec3d…

MALICIOUS

PDF

86.2 KB Created: 2021-09-02 10:02:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: b31e70b03488032093d2f074af1583b5 SHA-1: 809e4ce1ecaf466c5a1f57b7491737a4158755f2 SHA-256: 31429be05084ec3d96a083efc22a0131800496ce288115473f690b298209650b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct clues to the lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://ip-golubev.ru/ckfinder/userfiles/files/35583615074.pdf In PDF document text
    • http://banphimchuot.com/userfiles/file/78218002376.pdfIn PDF document text
    • https://vyaspublicschool.com/ckfinder/userfiles/files/66551807920.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160df955c089a8---nomunekazemolo.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/28294432032.pdfIn PDF document text
    • https://norservis.info/files/files/jegujajowekazamuximani.pdfIn PDF document text
    • http://hesexpo.com/img/editor/image/file/55141288415.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/2d92d0ea1243719c0e6df248612cffa9/rovepul.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/01f91cf887561550cfa65f263b073df9/donajuvasilimi.pdfIn PDF document text
    • http://flynewsletter.com/uploads/file/88964093677.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/i4jbl3gqllaic1648i1k5vmnqk/62619178390.pdfIn PDF document text
    • http://tlumacz-lipno.pl/pdrzewiecki/files/tebak.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a316a535b5c---lupajuj.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083ec02f11a4---filexobuno.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/3mlo96jq4rh8mpv0939oldg2kt/5346547666.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b49cec7d593---fikevesufevoguvuzutefi.pdfIn PDF document text
    • http://bannails.com/fckeditor_userfiles/file/51137813853.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/kogelaragofeboxofez.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089dd754d682---90491191902.pdfIn PDF document text
    • https://szelvedojavitasmiskolc.hu/files/files/godevulerigutuniror.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160afbec8ecb9a---70649905092.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/xuwegagusixu.pdfIn PDF document text
    • http://csss77.com/clients/d/df/df7f2fdc42e243c7a03c192a8228c0be/File/81809612056.pdfIn PDF document text
    • http://theloanwala.com/userfiles/file/sufutobutubonoti.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=what+to+do+when+you+feel+like+your+prayers+are+not+being+answeredPDF 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_off0000e77d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE77D 11304 bytes
SHA-256: 6282db22835c785852fdfb923457a6a9afc9d183d6c7430ef30f24c4a13647ee
font_01_sfnt_off0001019c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1019C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119AE 18024 bytes
SHA-256: 41d44e6130b0b4ec8acb4e58ddc6f037241c65742f4792259ac38d3717b28eb2