Malicious PDF — malware analysis report

Static analysis result for SHA-256 861844cd37ad0409…

MALICIOUS

PDF

85.2 KB Created: 2021-09-24 11:41:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 357f3e4dc6d738e57e575dc4d2344864 SHA-1: ac5fb9b5e7b322d91ac23c66dc86ec7f98325f5a SHA-256: 861844cd37ad0409bba5bcafe1a2af60069fd43703ba1611d971b1c220608627
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF acts as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. These links are likely intended to lead users to phishing pages or download further malicious content.

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://kurier48.pl/files/userfiles/file/zotakowipanujo.pdf In PDF document text
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/ratupovarulorofu.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613401e09fc6c---bolumunetanowetewuvak.pdfIn PDF document text
    • http://dison.cn/filespath/files/20210901051133.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/9e277d97cf9dc10c03d0da0f07b0ad8f/9442781777.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/85385475684.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/8bea350e6f7e3760b66625643db34e85/ruramo.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/4827217492.pdfIn PDF document text
    • http://hkalc.com/userfiles/pezamexugegaseve.pdfIn PDF document text
    • http://eszixv.hu/ckfinder/userfiles/files/zefunofadafibepajofas.pdfIn PDF document text
    • http://olympicthesportshop.in/uploads/31467862256.pdfIn PDF document text
    • http://p-itos.net/admin/userfile/image/file/81605313369.pdfIn PDF document text
    • http://originalbau.hu/imagesfiles/nejovivatogazet.pdfIn PDF document text
    • http://99hospitalitygroup.com/ckfinder/userfiles/files/kirufepamidaxasigoroju.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/lilomuxuz.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/xotepubizokixaxowipewi.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/13787966124.pdfIn PDF document text
    • http://bajajsports.com/userfiles/file/sunorepoledijuvo.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613182a55ca5e---zanexajapazad.pdfIn PDF document text
    • http://www.deewanalarab.com/up_imgs/46278698556.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=ctrl+j+chromePDF 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_off0000e90e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE90E 10132 bytes
SHA-256: 51a3d7f52bdebae598973205c10aaab7a989a1757e4f802b2c11d11e63d8b208
font_01_sfnt_off0000ffbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D0 18496 bytes
SHA-256: a821ecaf6ad7a1be5895965edca31b13574aaa70c7f09a1bc2dc123c57b0ee10