Malicious PDF — malware analysis report

Static analysis result for SHA-256 ebf5675d12f9f08a…

MALICIOUS

PDF

77.6 KB Created: 2021-04-08 23:42:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 615ffb32e59ba716bd2251bd77ace7e7 SHA-1: b1cd8308397f5fb78187dd8d709b8b697c173d72 SHA-256: ebf5675d12f9f08a9499ffd42b7ebcca368c83934f7d0235c8af8444452969c1
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to disposable domains and are likely part of an SEO spam or phishing campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, suggests a lure related to educational content, specifically 'online punctuation exercises for grade 5'. No scripts were extracted, but the PDF structure itself facilitates the redirection to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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.
  • 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://mezovuduw.ru/strik?utm_term=online+punctuation+exercises+for+grade+5 PDF link annotation
    • http://fejiximodanu.mygamesonline.org/bbc_compacta_class_11_english_answers.pdfIn PDF document text
    • http://koxivesuvif.mypressonline.com/active_and_passive_voice_multiple_choice_test.pdfIn PDF document text
    • http://nigemutekilum.mypressonline.com/free_printable_blank_bingo_cards_for_teachers.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/9cb93c3a-2e5c-42bc-b235-cef5e3211822/bexelaxano.pdfIn PDF document text
    • https://s3.amazonaws.com/rejiner/what_does_social_structure_definition.pdfIn PDF document text
    • http://zajupulavofawi.myartsonline.com/student_loan_master_promissory_note.pdfIn PDF document text
    • http://weparaxopulo.atwebpages.com/99864481236.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4618439-ad78-4f96-bb28-b9214905b035/kinh_thanh_cuu_uoc_cong_giao.pdfIn PDF document text
    • http://tofujuwo.onlinewebshop.net/how_to_get_samsung_chromebook_out_of_demo_mode.pdfIn PDF document text
    • https://6c639bf1-704a-4500-b661-329758898742.filesusr.com/ugd/02d620_c26ac02c5f224db79692d24aa206cc84.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/satudifin/polk_audio_magnifi_sound_bar_system_reviews.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a92e1b2-0645-4328-95a9-711cf7777ced/xugulijawekugipemowa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0ad9e0b-f92d-445a-b8ad-1aee3bfcbbfe/fe_exam_mechanical_sample_questions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/58cd13a3-beb4-4e79-b5ff-f5ca9b2a7143/84915888920.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/059de208-9444-48d1-9cd2-0c0c49422616/military_alphabet_chart.pdfIn PDF document text
    • https://a7563df4-ba19-4d82-a8a0-b2470d957038.filesusr.com/ugd/61f964_61b5d1f7f20f43f7b04a08f41ab06d38.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xuzakob/multiplying_decimals_worksheet_6th_grade.pdfIn PDF document text
    • http://raxajabidadida.onlinewebshop.net/alginac_100_bula.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a7951d53-63ba-463a-b403-b2e09d6b67df/79582227172.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a51a4809-27d0-4aeb-bbac-f482817232a7/derecho_romano_margadant_libro.pdfIn PDF document text
    • https://s3.amazonaws.com/gotijejaj/abo_sadam_whatsapp_apk.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF054 5540 bytes
SHA-256: 598297f6625694cac1e1228689bf1dab432452a2aaf6792857af5af8d5d333c9
font_01_sfnt_off0001033e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033E 11180 bytes
SHA-256: 45c63f677457834fd574d6410b15e9b491a6eb4cdbd15a2be4668c4ad547981c