Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c7a85e6776b655…

MALICIOUS

PDF

79.2 KB Created: 2021-03-22 20:43:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: b4f4a2fe233a728dbba9755586db6916 SHA-1: b21d86c7e8f943ad78cad1b1b6df756a8864b738 SHA-256: 28c7a85e6776b65581b766c504528b586b9560d9eee441cf84f09adba9118743
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file is classified as malicious due to its extensive use of link farms pointing to potentially harmful websites, as indicated by the PDF_MALICIOUS_REDIRECTOR_LINK and PDF_SEO_LINK_FARM heuristics. The document body, though heavily obfuscated, contains text related to Excel VLOOKUP examples, likely serving as a lure to disguise the malicious intent. The primary goal appears to be redirecting users to external sites for phishing or malware distribution, leveraging techniques like spearphishing attachments and potentially exploiting client execution vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • 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://dafemum.ru/123?utm_term=vlookup+in+excel+example+between+2+sheets In PDF document text
    • http://sdek-24.cc/40058866496zd14m.pdfIn PDF document text
    • https://cdn.sqhk.co/pabelewexo/jGC5ja1/fm_radio_app_without_internet_connection.pdfIn PDF document text
    • https://cdn.sqhk.co/pesasotiro/vagdeNc/archipelago_presets_review.pdfIn PDF document text
    • http://cardioactiveitalia.site/apple_app_store_for_android_apkgahiy.pdfIn PDF document text
    • http://mojenisijita.mywebcommunity.org/anestesia_epidural_y_raquidea.pdfIn PDF document text
    • http://sopugepibimel.mypressonline.com/mukimepifubenexulo.pdfIn PDF document text
    • http://nutetuxiv.mygamesonline.org/fidakozasokalozo.pdfIn PDF document text
    • http://zimezobot.getenjoyment.net/creative_visualization_book_summary.pdfIn PDF document text
    • http://pidawudimo.scienceontheweb.net/libros_de_mario_benedetti_gratis.pdfIn PDF document text
    • http://dusibarupuguli.medianewsonline.com/rappel_anatomie_physiologique_de_l_appareil_genital_feminin.pdfIn PDF document text
    • https://cdn.sqhk.co/dutaxato/GgehcmQ/83670810720.pdfIn PDF document text
    • http://4gusevshop.space/nobel_prize_aquaporins_worksheet_answer_keyymiv8.pdfIn PDF document text
    • http://jirenaxapibetig.scienceontheweb.net/66802441195.pdfIn PDF document text
    • https://cdn.sqhk.co/bisuligiga/DhayhcN/introduction_to_business_studies_class_11.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wutejaxevewef.myartsonline.com/arenes_chemistry.pdfIn PDF document text
    • https://3cd6846c-369c-4875-9c63-132df726a2dd.filesusr.com/ugd/7ab50f_ecf9d244c73d48d8b0363d60361f4f1d.pdf?index=trueIn PDF document text
    • https://92fed17e-af34-466b-b3fe-38cd9ef27699.filesusr.com/ugd/192d58_9508752f9b4d40a7aad863807221d666.pdf?index=trueIn PDF document text
    • https://9c33b4df-6f14-41ad-9e94-a3a23f7ed20d.filesusr.com/ugd/2a975f_cbf63698b5f548c8a1865c71379a297b.pdf?index=trueIn PDF document text
    • http://zepizevut.atwebpages.com/zosajoxipam.pdfIn PDF document text
    • https://9fbaa0db-fe9e-443e-b503-3d02ea494c21.filesusr.com/ugd/d417e9_3d38c970430f401c9ea16b86163bf553.pdf?index=trueIn PDF document text
    • https://ed21222e-fee3-4fab-8b52-e2ddb7bb35ab.filesusr.com/ugd/e73fea_f1d5d8667d36472899af25294fe0ed53.pdf?index=trueIn PDF document text
    • https://bf808793-8b46-4c54-8b11-319763181fa0.filesusr.com/ugd/0d018b_e0fd8d58ff0a41118806fed0b49efd1a.pdf?index=trueIn PDF document text
    • https://e3055f73-6236-423b-b810-4bc1a15f300f.filesusr.com/ugd/fa12d1_0bc028343b63420bb885d127e0cdae64.pdf?index=trueIn PDF document text
    • https://de99c131-68bf-4271-bcef-cda292486844.filesusr.com/ugd/f5892c_7922d6966d7441f793a991e4101cf5bc.pdf?index=trueIn PDF document text
    • https://da4cb982-96ac-4827-b01c-1601b1c9977c.filesusr.com/ugd/b05c40_5e13e06b15a74fd590592f53f3fac105.pdf?index=trueIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f56e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF56E 5540 bytes
SHA-256: 11516756b28311e3866208118349e109c368927eb73a94abf150c2186703e430
font_01_sfnt_off0001083a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083A 11428 bytes
SHA-256: 6f4b6d822dc675b3ddd167247b78e5f76b24e86ef4e916d3a61731aa19ce0659

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