Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f91b0f13c18d9b4…

MALICIOUS

PDF

74.9 KB Created: 2021-09-09 10:57:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 74a6d12b40e31398219ec377ff82affb SHA-1: 5e795379dada1634628bd42ec05648a733bb90be SHA-256: 1f91b0f13c18d9b4411c7b495aee37b21a9a668d18327c664123d002de063b75
156 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ClamAV and an ML classifier. It contains a link farm with multiple URLs pointing to disposable hosting, suggesting an attempt to distribute malicious content or phish users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for a large number of links, further supporting this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://delta-serwis.pl/pliki/55071620016.pdf In PDF document text
    • https://www.bbmnetlicitacoes.com.br/cms/ckfinder/upload/files/23226253281.pdfIn PDF document text
    • http://tutaylamhet.com/storage/ckfinder/files/75571773145.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/161319d60c653d---sokazebamafuza.pdfIn PDF document text
    • http://dealershop.es/camarasegovia/userfiles/file/87874489202.pdfIn PDF document text
    • https://zahidnawaz.com/UploadedImages/image/xijaregaxodug.pdfIn PDF document text
    • http://esistore.de/userfiles/file/vavuzipez.pdfIn PDF document text
    • https://eletmodguru.hu/files/files/3704735790.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16137bc24b5756---32198197336.pdfIn PDF document text
    • http://syarmarka.ru/userfiles/files/linanozisotibidibexivaf.pdfIn PDF document text
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/64328960999.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16138c2408cb35---23954231971.pdfIn PDF document text
    • http://iwort.de/userfiles/file/58055256798.pdfIn PDF document text
    • http://tabletopad.com/images/file/77432240426.pdfIn PDF document text
    • https://www.htlexpress.com/ckfinder/userfiles/files/85458903206.pdfIn PDF document text
    • http://efcosmetic.com/uploadfile/files/94298647695.pdfIn PDF document text
    • https://twinslock.com/locktactyuma/userfiles/file/59987600750.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/34913650094.pdfIn PDF document text
    • http://hai-bi.com/uploads/files/202109080745377293.pdfIn PDF document text
    • https://mimpiindah1.com/contents/files/vagunopozavuze.pdfIn PDF document text
    • https://pikhospital.com/ck_uploads/uploads/files/febaxexovetejujuvubufukiw.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/75190648740.pdfIn PDF document text
    • http://susutour.com/userfile/file/zorelo.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/37310999654.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+remove+snapchat+filter+off+photoPDF 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_off0000c1c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1C3 10888 bytes
SHA-256: dea7dcc9914e43257d9714c77a29fbb7f565f27169a320e212c21202944a7dba
font_01_sfnt_off0000dac7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC7 16796 bytes
SHA-256: 86bcf22c7db5ac99c16ceb8b3d57c4c84b9a2590b126bb139569285927e50be3
font_02_sfnt_off00010589.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10589 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1