Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b8916c1f443f26b…

MALICIOUS

PDF

94.8 KB Created: 2021-07-02 12:04:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: d53949f7f2697b33807cf45ada1d1f8d SHA-1: 83ab86b8713d75f38803acb63e8bde98815a6251 SHA-256: 8b8916c1f443f26ba368bd0f5e91a0f050f8fc2dec9233c4451974e1052fea79
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating it likely contains an exploit. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites. These sites, in turn, host further PDF files, suggesting a multi-stage attack designed to obscure the ultimate payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16071d240450af---bonoguxive.pdf In PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/ebaf1a6d5006ff2f666a00e1bfb5b155/73169486722.pdfIn PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/beziwiledegoxevabumolato.pdfIn PDF document text
    • http://wowbond.com/upload/Fckeditor/file/kaxevaxuzogejunuvugezuko.pdfIn PDF document text
    • https://associazionedynamica.it/uploads/file/nigufuvobaj.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210514105339_1277770413.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/68634283126.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/l97dnqm47v26nho4aosm1u0124/74920327843.pdfIn PDF document text
    • https://spacio.hk/attachment/file/1206603901.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/b4fdf84897b1ce9956a2fd5352123f5d/96760350696.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609702e735dcd---79945084730.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/26396782333.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac46b32d3a0---82069003939.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/c1996349d92ee30098502a5c90c938f6/35107754725.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/6e9ee65917f60215405b6fe85193f6ff/fekopififudosuwop.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a440ddc4caa---sovovepujijatejavulimad.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16099cf9abf421---18054282560.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ea6d2c12d---66852310056.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609852cdea259---68464705307.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/1daafba9dedaaa9253d2ba10178d3959/90051374706.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/qt5hb0itks8tladqh72c0p8n81/29219475506.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/xafoniwejobiworezobituve.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9c7e28ef3---nobitetonebuzexana.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a976409f0d8---60166697128.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=human+body+systems+study+guide+answer+keyPDF 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_off00010ec0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EC0 11068 bytes
SHA-256: 2357555f6ab3154dd5f5e2483a4fc74ff8162ce5c15d6e37bd38d52a51c4cc85
font_01_sfnt_off0001285d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1285D 17456 bytes
SHA-256: 4134ccbcfa0e84effe8d9b0993bbaabafeb084d3a873ba9964fe4a27df9313e0
font_02_sfnt_off00015570.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15570 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1