Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8532e71cd869fdd…

MALICIOUS

PDF

86.8 KB Created: 2021-09-13 00:26:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b2ef8e7b77e354f3dfa18afe9f6c9d45 SHA-1: 87bd8bcfb1ea15e97b068bf3214631dd27ed9d7d SHA-256: f8532e71cd869fdd58156eb93e9d862e32ba1ab4af1b5e659d8cd6db797ffe59
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm on disposable hosting, with one URL pointing to a compromised CMS upload. The ML classifier and ClamAV also identified the file as malicious, specifically as a phishing trojan. The presence of numerous unknown URLs suggests an attempt to direct users to various potentially malicious download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9765

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 https://zivotzaokny.eu/res/file/2868567467.pdf In PDF document text
    • http://www.lebedosapartotel.com/data/yukle/files/66253446123.pdfIn PDF document text
    • http://jeykrishnaclub.com/images/file/85924730032.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/29898950917.pdfIn PDF document text
    • https://daynexweb.com/upload/ckfinder/files/99199708326.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/sosowokinozetamam.pdfIn PDF document text
    • http://bitree.net/ckfinder/userfiles/files/68242040396.pdfIn PDF document text
    • http://extintoresorigen.com/images/editor/wulijibajebekawup.pdfIn PDF document text
    • http://ansonseatery.com/uploads/files/wupekunuzesese.pdfIn PDF document text
    • https://skillmapmagazine.com/ckfinder/userfiles/files/bilifadi.pdfIn PDF document text
    • https://ducthai.vn/userfiles/file/72195103458.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/51900897564.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/cbc86947e62de03abdd19509b52cfd24/73343474040.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/6812760013.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c73d510fbf---35371310618.pdfIn PDF document text
    • http://hissekurban.com/resimler/files/lugogijanosukudomilitulas.pdfIn PDF document text
    • https://y3stwk65l-mn9.com/contents/files/molenojuw.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613148b88aadf---noxotojaluxabokaka.pdfIn PDF document text
    • http://villacappuccina.com/userfiles/files/mukemapupa.pdfIn PDF document text
    • http://advocaatindex.nl/images/uploads/78113646672.pdfIn PDF document text
    • https://hargagila.com/uploads/image/files/detozafanilaz.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/47854183795.pdfIn PDF document text
    • http://filippodelvita.com/demo/userfiles/file/zopimevakusafo.pdfIn PDF document text
    • https://palet-school.com/files/files/52761400406.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/81694171477.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/61587061357.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=gta+no+root+apkPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD903 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF110 3040 bytes
SHA-256: a3baa07c31d6547272c1c2e8a219524a1aa08e3e84aefe1b256678547359b2fa
font_02_sfnt_off0000fdb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB0 9940 bytes
SHA-256: 110cb0d754f15b26ece8c14196bdb96cac508948eccb8a8b89fcda8a65c6145d
font_03_sfnt_off000113ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CA 22540 bytes
SHA-256: 4ee328dd54cc35ec231352197012dd9f4166c1317363aeff76f25a6b3f14ae23