Malicious PDF — malware analysis report

Static analysis result for SHA-256 999c19ead334b808…

MALICIOUS

PDF

88.9 KB Created: 2021-09-24 08:30:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f77cd91803459a3c62429f9e39f406a9 SHA-1: 8d24c615edc7acb26b75d5e7f84d314c05619974 SHA-256: 999c19ead334b8084f01b5a2067dc673312ca91ff605c7ffe78976debe0eee9a
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely intended to lure users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/abcaf9c5a38bc41b6dc7833dab3317ad/82941085676.pdf In PDF document text
    • http://vkts.se/userfiles/file/widexoli.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/radawosepewivesibev.pdfIn PDF document text
    • http://gaineyranchaz.com/userimages/mupemufexolulafa.pdfIn PDF document text
    • http://zsmnowakowski.pl/userfiles/file/tibapasiralamebawifu.pdfIn PDF document text
    • http://sourceit.ke/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/48528661577.pdfIn PDF document text
    • http://rapet.hu/files/wujazafupajuzixabojerile.pdfIn PDF document text
    • http://goldcoil.com/uploadfiles/files/pusegurofozo.pdfIn PDF document text
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/pokilo.pdfIn PDF document text
    • http://artsar.pl/userfiles/file/lofedemutodeg.pdfIn PDF document text
    • http://aucoindeshalles.fr/menu/file/78204229821.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/rivutawo.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/tewepakobebejarusavewojiv.pdfIn PDF document text
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/xazasumukirovab.pdfIn PDF document text
    • http://hissekurban.com/resimler/files/tifalotuj.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/161460f6d4a70d---79479127059.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210909_69622BA7B7F44EF7.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/730839943.pdfIn PDF document text
    • http://pytextiles.com/userfiles/file/tojetelateburenasopo.pdfIn PDF document text
    • https://dentalrud.com/userfiles/file/84552678046.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/vagudabofikewugonewaluniw.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/lukerumidigekaritado.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1614809b44fad4---timorosajezofesoradop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+get+voicemail+icon+on+androidPDF 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_off0000f3a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A0 10688 bytes
SHA-256: 1cff08545e85ca9cfc7d4c775bf044850f6e302c8dbdd97dae4a55eaa395b09d
font_01_sfnt_off00010be5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE5 19288 bytes
SHA-256: 2ff4a44e66facdcc55de79c9349cc9513506b22ba65de24cf7a815bfb77f594f
font_02_sfnt_off00013d7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1