Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e246499e8163bf6…

MALICIOUS

PDF

104.9 KB Created: 2021-09-09 00:02:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d9a202de4181302801ca55c5702ca041 SHA-1: 14e0aaab951209214cf79c5c35934d825815b418 SHA-256: 4e246499e8163bf6e3d368bd5a1266e8118c6c0fa297e9f65e083ec90cf97b4c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS uploads. The ML classifier strongly flagged this PDF as malicious, suggesting it's part of a distribution or redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 5

  • 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://nacyc.jp/Upload/file/semuxobosugeragi.pdf In PDF document text
    • http://b40555.handyfriendship.com/upload/files/fuxanupesavigiburi.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/43999567721.pdfIn PDF document text
    • http://mmsmarin.com/imgimage/file/musasikejijifesu.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/61132168659.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138b114c5fb2---69990145827.pdfIn PDF document text
    • http://purplebyanki-com.bvirani.com/ckfinder/userfiles/files/niwepaw.pdfIn PDF document text
    • https://xn----7sbeo1acdy3adh.xn--p1ai/userfiles/file/bakixitor.pdfIn PDF document text
    • http://f1-rennsimulatoren.de/userfiles/file/tofepamowurarozewanilux.pdfIn PDF document text
    • https://specializzati.tecnaevolution.it/dataload/ckupload/81879671650.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/27719578337.pdfIn PDF document text
    • http://revistaspontan.ro/assets/ckfinder/core/connector/php/uploads/files/94885848088.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/kegazikofozudimitur.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/7078f27ad404ea4eaf29ff4d3777c8d7/xobupimakizakojaxejo.pdfIn PDF document text
    • https://agri-mal.pl/userfiles/file/99836322909.pdfIn PDF document text
    • http://gniortho.com/files/Upload/file/87581687331.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/8487335832.pdfIn PDF document text
    • http://metalzilembo.it/userfiles/files/22151248332.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/jofipeniwibimoxon.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613405b182c20---temajepobakowefaf.pdfIn PDF document text
    • http://checopharma.com/upload/files/18564551560.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/53851985260.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/458a03d2a88783f56eb802edf3b5dd80/gejedudomiwarulunosoj.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/tanuvumokimevidagarevasef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=curwen+kodaly+hand+signsPDF 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_off00013230.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13230 10852 bytes
SHA-256: 8be873bce1ec1def946cbd30b3296f661804a1727790dfa380f8170078cbc84a
font_01_sfnt_off00014b09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001631b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1631B 19568 bytes
SHA-256: 16b8d9e732c87b6a9325532ed0ccacbd3a563c246fe8d62718d5511015e28f1a