Malicious PDF — malware analysis report

Static analysis result for SHA-256 fbdb71ba18596ed6…

MALICIOUS

PDF

84.6 KB Created: 2021-09-20 20:19:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: aa0cf8964b8b4aaef9cac78308367e4a SHA-1: 9aef14109c2065772a1caf392f55c073db50e918 SHA-256: fbdb71ba18596ed6c2237439f82d525157838ee9a1521911672a558402e79a7a
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings strongly suggests the document's purpose is to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161437adc546fc---kamafetizataxewuw.pdf In PDF document text
    • http://xn--o39a91gvwm83kbsn.net/FileData/ckfinder/files/20210919_1147EFABF683487F.pdfIn PDF document text
    • http://balcimimarlik.com/resimler/files/notelafemisumivenirir.pdfIn PDF document text
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/46326154920.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/77111252216.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/52105265556.pdfIn PDF document text
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/98836170009.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fccff828c9---17195328407.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161457e64c04e3---8073462391.pdfIn PDF document text
    • http://hla.vn/upload/files/lijovodizaludewupufutil.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/16148049d8048e---tebuzutuv.pdfIn PDF document text
    • http://parkergeneralcontractors.net/userfiles/file/11678792165.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/18640956310.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/31892849328.pdfIn PDF document text
    • http://jhdjt.com/images/upload/File/97409901143.pdfIn PDF document text
    • http://agt.es/files/galeria2/files/31969231621.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/ponomuzafasifeda.pdfIn PDF document text
    • http://innovad-ltd.com/userfiles/file/23764697397.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/14267118927.pdfIn PDF document text
    • https://praktijk-fix.nl/userfiles/image/file/71030945917.pdfIn PDF document text
    • http://ndt-ultratech.com/files/suroragop.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140e720307da---mapemojekoguziwezu.pdfIn PDF document text
    • http://www.phuongdonggolf.vn/app/webroot/uploads/files/33626685908.pdfIn PDF document text
    • https://ibliberia.com/ckfinder/userfiles/files/sidisamepa.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/82849680182.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=the+wonder+weeks+ebookPDF 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_off0000e633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE633 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE4A 10228 bytes
SHA-256: e28592fca698ac859d5862773a6eb00e161e4d7fa2708599748b1badbab5bb3f
font_02_sfnt_off00011537.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11537 18168 bytes
SHA-256: d7972e0ea75825e5806c7f0ccade680b1a62becf79fbbcafd96ef9c8aff3d2d1