Malicious PDF — malware analysis report

Static analysis result for SHA-256 837d5a5d49992c44…

MALICIOUS

PDF

94.8 KB Created: 2021-04-05 00:41:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: fee5d6dc5220a40d3274e9293c4e05f3 SHA-1: d527d31df2d15ec2f8b312d8933b8b83a08883b1 SHA-256: 837d5a5d49992c449096c1384b88c595d2327498d5621be4bc201d091c1329cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous external links, with a critical heuristic identifying it as a link farm. One prominent URL, 'https://jacksth.ru/award?keyword=poetry+analysis+worksheet+pdf', is presented within the document body, disguised as a poetry analysis worksheet. The presence of a ClamAV detection for 'Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0' and a high ML classifier score strongly indicate malicious intent, likely related to phishing or SEO poisoning to drive traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://jacksth.ru/award?keyword=poetry+analysis+worksheet+pdf PDF link annotation
    • http://nurigoluda.mygamesonline.org/pafoxutojus.pdfIn PDF document text
    • http://volelovapudexif.scienceontheweb.net/aspirina_protect_en_el_embarazo.pdfIn PDF document text
    • https://cdn.sqhk.co/wobuwozavenu/cidqjfd/new_york_city_winter_iphone_wallpaper.pdfIn PDF document text
    • http://jawunefuda.mygamesonline.org/sopuvuvijufalalosuke.pdfIn PDF document text
    • https://cdn.sqhk.co/gipakegabav/iyYidvA/fuzojokisedojoraxopape.pdfIn PDF document text
    • https://cdn.sqhk.co/vapezuwe/gechihi/sports_car_racing_app_store.pdfIn PDF document text
    • https://cdn.sqhk.co/vexorikodo/jfOjjgj/36439520774.pdfIn PDF document text
    • http://kimidenexikox.getenjoyment.net/44323000661.pdfIn PDF document text
    • https://cdn.sqhk.co/kugefiruxat/iUgcb9L/28592024285.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/vebenok/room_impulse_response.pdfIn PDF document text
    • https://a72b158e-cead-41d6-a0b3-8518216316a4.filesusr.com/ugd/35c6e2_48f52c0d046d4a8e9638fc99c8c6f6cb.pdf?index=trueIn PDF document text
    • https://1f2f8e77-98df-4c5e-b88a-83bc2b612b58.filesusr.com/ugd/5c7528_60a994a0f3ba4c53899d67c17c34456b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3dcab3ce-a8bc-4b89-bd44-c0e0926b995f/contabilidad_de_costos_ejercicios_resueltos_excel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a774002-1c51-4513-b098-5ead496910ea/scl-90-r_validity_scales.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9520ac91-9345-40fc-b22b-046556dccf87/centripetal_force_meaning_in_bengali.pdfIn PDF document text
    • https://s3.amazonaws.com/dinigugaxej/sodopafekodosefukavunuk.pdfIn PDF document text
    • https://s3.amazonaws.com/wumodukubaru/64891290948.pdfIn PDF document text
    • https://s3.amazonaws.com/vukujidor/kitirekumidapesos.pdfIn PDF document text
    • https://s3.amazonaws.com/rabewiruzitewa/78335435194.pdfIn PDF document text
    • https://s3.amazonaws.com/sizadagazagaj/pozapida.pdfIn PDF document text
    • https://s3.amazonaws.com/bexolamabad/glorious_morning_waterflame_sheet_music.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/37a0807d-e2f8-41e8-96d0-2cb3079661e1/mezexezidaxegipegovod.pdfIn PDF document text
    • https://fec450ea-b80f-4746-b851-35139cc02de5.filesusr.com/ugd/53a83b_19cb2e91376549b9b87aec1febc053b3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0da046fe-fd2e-4248-9890-c80324ee91d4/which_of_the_following_is_the_definition_of_public_relations.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://scripts.sil.org/OFLIn 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_off00011ca9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA9 5388 bytes
SHA-256: 8f8c238c979b306444ad4245aabed0bac930ae1a31f1922babce9adbc63199e2
font_01_sfnt_off00012f11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F11 11964 bytes
SHA-256: b15c58a3b46c78a4429aa0520723dc51bc1df86603dcbd52430be45a928b7a81
font_02_sfnt_off00015845.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15845 16136 bytes
SHA-256: fa37d3a82dcac8108608dac580e02fcb346e9d7e494ecb37de828bc973da3738