Malicious PDF — malware analysis report

Static analysis result for SHA-256 31e10ddea5a03cbb…

MALICIOUS

PDF

87.3 KB Created: 2021-07-14 04:15:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: b9c09a4361e914e419e66bd0132266a2 SHA-1: e3a5813f206f32c2a615168ef3c58fbc4dd74e4b SHA-256: 31e10ddea5a03cbb21489e98a9403c4e1d36c13a8dd2fba13514a23df113ae8f
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites. The embedded URLs suggest an attempt to redirect users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607491fc5d048---90535570659.pdf In PDF document text
    • http://mousike.it/img_ins/files/sewuwikojomixu.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608510f69cb0f---81290977258.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/fewobajeno.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2343cdf1be---gotuvamawo.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e0244c45d3ed92a7cb0be39f90dcd3e1/sivatukekabuletaromap.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/rjob5jlc9qpe11fvkqm4pngot7/63742327143.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/ktnilq13a6b92ges5dcnm8d6m6/gofaselojenapasa.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/577e6717323e9c14ec1107417dfe668c/52303486034.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ef3fe859a---metumuleribasawokivokex.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/valasimuwax.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0dad5c59f---52451242625.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160846174d140c---17863035449.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608083d6d1460---dafogezazapaf.pdfIn PDF document text
    • http://pk.mo/userfiles/file/49405562311.pdfIn PDF document text
    • http://skomi.ru/img/files/file/sifepafamiwi.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/eaa647dd6ccab7385120926b5ee7ea8a/gifedipogi.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8ff729195---wavenexolefewakubatofipod.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/digexiwalemujirikitob.pdfIn PDF document text
    • http://fairtradeportal.pl/userfiles/file/67944253105.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b5d9dbb7b00---rezijegugofadex.pdfIn PDF document text
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pofufitilidebunikizutaz.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/a900e7ffc431db4933bf2a4f677aef47/fibugexedidukubawuguxoxo.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb4e97c214a---bilegatoduwudomijugitavu.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/83232321392.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/88719540806.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=production+of+hand+sanitizer+pdfPDF 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_off0000f0ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000108ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108FF 17592 bytes
SHA-256: 2d78697cc48d066ca024c5419d4b36e0b812cb74eab9ccae7c10bb6c8af0df75
font_02_sfnt_off000136b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136B8 10832 bytes
SHA-256: 0ab740560171a50fb762f3de086cf13bef737526c4c7528e623dd7dcc47b4d8b