Malicious PDF — malware analysis report

Static analysis result for SHA-256 82146c19ac066f31…

MALICIOUS

PDF

75.9 KB Created: 2021-09-12 02:16:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 05b5e326cde5c72150e88b82628cf3d7 SHA-1: 39db59dcffe3ae1b5740834d6e8b77fd20f4e910 SHA-256: 82146c19ac066f31a023d15e402402c981ebd28c762a7f797daa758cf164dc2d
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to other PDF files hosted on various domains, indicating a link farm. Several heuristics confirm this, including 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier also strongly flagged this PDF as malicious. The presence of numerous links to external files suggests an attempt to lure users to malicious content or facilitate further infection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://takitech.hu/userfiles/file/33385265992.pdf In PDF document text
    • https://quangcaowebsite.vn/uploads/files/redelexozifiladeruna.pdfIn PDF document text
    • http://lycee-elm.info/userfiles/file/11159062931.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/warorawof.pdfIn PDF document text
    • http://saint-party.com/media/file/zuvupamunojekupatudovalim.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/luvadenemetozez.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/javumibudobekikuduleweg.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210912_092CF48AF98ECF8C.pdfIn PDF document text
    • https://dmshospital.com/mm_engg/files/negadutilizisuguwo.pdfIn PDF document text
    • http://bantinnhadat.com/users/files/17357891275.pdfIn PDF document text
    • http://angelascanu.it/uploads/file/66625392424.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/mabobowi.pdfIn PDF document text
    • http://sineadstone.com/userfiles/file/kowukatem.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/juzuwekojinutumifebe.pdfIn PDF document text
    • http://rudolphalexander.com/uploads/files/jinufafejupuxozevowegipis.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/wemoduf.pdfIn PDF document text
    • http://rheumatology.institute/upload/content/file/17410347662.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/e422369dd584d8b822ec97132111e13e/lurixikorudogudul.pdfIn PDF document text
    • https://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/29093104238.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133325fa3e81---4054552734.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1613d277499647---47621414597.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/nijojetikipi.pdfIn PDF document text
    • https://ciiinnovationsummit.com/ci/userfiles/files/30984285537.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=download+raging+thunder+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c54b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC54B 16724 bytes
SHA-256: 2c7aa35f111075aa89fdef165032d8574526213acf151c4c97099f3e10fdc92b
font_01_sfnt_off0000f099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF099 10784 bytes
SHA-256: 69dcbc37f11968d2b2176c7672b295644e5e2ab6278c883dea13fc6628c58e6f
font_02_sfnt_off0001092c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1092C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1