Malicious PDF — malware analysis report

Static analysis result for SHA-256 6231e9e6cfc73dbd…

MALICIOUS

PDF

85.7 KB Created: 2021-08-18 18:52:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4dd9189b81459d07176041fc8153172b SHA-1: a5e1d30e2e35ede4ba234aa4fbfd176e6f4653b7 SHA-256: 6231e9e6cfc73dbdc4e7531a0b39ea91a727b6a2e38a4b2e133738fcabb9775a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document functions as a link farm, containing numerous URLs that redirect to potentially malicious content. The presence of multiple links on disposable hosting and compromised CMS upload storage suggests an attempt to obscure the final destination and evade detection. The ML classifier strongly indicated maliciousness, and the structure points towards a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://smidgel.ru/uplcv?utm_term=resignation+letter+for+school+teacher+pdf PDF link annotation
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/d2hptacvpk57qc9vqhpl71e2hi/xepixurexikalubazufubi.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/92bea4ae8c0fa0bf7f8e2b62589b71ae/vamivufe.pdfIn PDF document text
    • https://jhservice.net/imagenes/galeria/files/zakezovixanukegorasoju.pdfIn PDF document text
    • https://www.nevjegykiraly.hu/userfiles/files/29502877250.pdfIn PDF document text
    • https://biomedchita.ru/imeg_master/file/vinipedap.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/8661a5f5d61862c11ff98e99e34ca57a/dosoga.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3ffcaad9bf---togoxixapozopuzeraz.pdfIn PDF document text
    • https://digireg.com/upload/xezema.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/182aa55a1b58296a834fc9b74a211832/kafidelelarimovemasiles.pdfIn PDF document text
    • https://immobilgold.com/file/bexepiluzadedodowux.pdfIn PDF document text
    • http://fashioneducation.ru/userfiles/file/relizoligapuredovirewakeb.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/f0ukajbocovv8qiqbvun2dvss3/katozibipirafulitamuri.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/45047816299.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160893556ce2de---70530319552.pdfIn PDF document text
    • http://daotaonhaccong.com/uploads/userfiles/file/jatafuwup.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16092602ad2049---66941537064.pdfIn PDF document text
    • http://namngonviet.vn/user-/files/perigeparazi.pdfIn PDF document text
    • https://fentesmakina.com/paket/upload/files/lasefumar.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/furewefewomeniwumaxazabu.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160bfea2534b3e---seduzulutax.pdfIn PDF document text
    • https://pemaboutiquehotel.com/assets/userfiles/files/tiwotelitakipokixofede.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/e478dca491b419738ce7a579ac9f5578/92307620643.pdfIn PDF document text
    • http://cu-mbc.com/ckfinder/userfiles/files/93823969628.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/12967789242.pdfIn 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://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_off0000e9c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9C1 10944 bytes
SHA-256: be0d5913b90599c55be18730ff7d115a83b8bb850bfbe1470465bf9183323002
font_01_sfnt_off000102e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011af3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AF3 16748 bytes
SHA-256: 1c586eb8d48afff7e40314fff7bcfdf42a64897842e74a8a01352118e0836a85