Malicious PDF — malware analysis report

Static analysis result for SHA-256 a20ed7c37807f59f…

MALICIOUS

PDF

93.6 KB Created: 2021-07-20 12:00:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b6aa2719debf3cbb0997618cf0fa8ea6 SHA-1: 08082f43b3f2b94b24f403b000e1e7535b2b6732 SHA-256: a20ed7c37807f59f797e4224e728717e3e53b1b86cb5f41754777568cbf71cd3
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories and disposable hosting, indicating a link farm designed to obscure the final malicious destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://riondene.ch/img/uploads/file/52391554830.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8e7d420fd---7845824875.pdf
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/07uj46uh3egl1gthvdktunm35c/kewapudumuninetobesudalof.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608415e33e03d---81314769273.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2db78ce84---jibibufikebo.pdf
    • http://sitoad.com/bbqjoekey/files/202106242322321279.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d054669f77---58056249938.pdf
    • https://mauspro.net/upload/files/vukeba.pdf
    • http://the100voicesofgospel.de/fichiers/newsletter/file/4312125920.pdf
    • http://chickendaylacrescenta.com/uploads/files/kiwaviwitesunawige.pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607037fc4d559---falujatemokonafododupu.pdf
    • http://alexlunacoach.com/img/editor/file/wozevuxuweguva.pdf
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607170d60a931---27365773197.pdf
    • https://agrimal.pl/userfiles/file/rojajaz.pdf
    • http://charivne.info/images/file/63215098809.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d08fa8de064---boridodopepifogo.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/lerq5kq0qffql83c31t2vh87g4/6738862448.pdf
    • https://abugfreemind.com/userfiles/file/27821794048.pdf
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/3cbdd559378666ae0a89dc12639479ee/tikadozokatinebafivozuler.pdf
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/d327fa4287d49d8d73bed3bd38bc24a9/wejugurugalosugavi.pdf
    • http://www.tobywells.org/media/fckdir/file/52465440195.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607321cdcc330---25943073332.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/31bb88b67100c7eab8a8a888d352b052/13902688276.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=school+social+work+interview+questions+and+answers
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001091d.bin
aa821a3da4a716954fca90f4dcc473d1404a030ac9ab9a5c2a2e3943b4418e6e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1091D 17636 bytes
font_01_sfnt_off00013793.bin
1aa15fd4ed40c46adf02f121a5ca5270479676463c8cc6d161474cfd20b03e89
pdf-font-stream PDF embedded font (sfnt) at offset 0x13793 11032 bytes
font_02_sfnt_off0001510b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1510B 16792 bytes