Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7bb51a33ad2557e…

MALICIOUS

PDF

75.2 KB Created: 2021-03-31 17:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 5f538b0092aff8baa69a98771c03ca2f SHA-1: 2697391677b173c2f78449bf1d99df7658fe42a1 SHA-256: a7bb51a33ad2557ea5bbd9de0e625c8ea171b3c095c11a4de193772ec95858e3
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. It contains numerous embedded URLs, with one specifically identified as a link farm on disposable hosting, suggesting an attempt to redirect users to malicious sites. The presence of PDF_URI and ML_NYX_PDF_MALICIOUS firings strongly supports a malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 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://vilenefex.ru/award?keyword=livro+candlestick+em+pdf PDF link annotation
    • http://circus.market/international_journal_of_research_and_analytical_reviews_publication_fee3jgkl.pdfIn PDF document text
    • http://presentinsta.site/spectra_s1_not_workingehmz8.pdfIn PDF document text
    • https://cdn.sqhk.co/pagozixupezi/fjgrhin/caller_tune_song_lyrics_in_english.pdfIn PDF document text
    • http://martakkord.ru/talabixibozijevaviziwemetksl1.pdfIn PDF document text
    • http://watulexop.iblogger.org/computer_networking_jobs_salary.pdfIn PDF document text
    • http://eurofamily.pro/jeep_wrangler_body_partskbv9l.pdfIn PDF document text
    • http://lovelyhouse.online/ti-84_plus_online_calculator_no_downloadu5da2.pdfIn PDF document text
    • http://keksik24.ru/718463462783gryj.pdfIn PDF document text
    • https://cdn.sqhk.co/reriwoduriju/gcCdk69/genidigujupebakewibidop.pdfIn PDF document text
    • http://repair-kvadrokopterov.ru/pets_at_home_dwarf_hamster_care_guide40lkt.pdfIn PDF document text
    • http://pokemonrivals.online/nuzuwoo15a2.pdfIn PDF document text
    • http://am-sound.ru/27041894155lpoby.pdfIn PDF document text
    • http://suruwafid.22web.org/blacks_law_dictionary_6th_edition_online.pdfIn PDF document text
    • http://sexogovo.iblogger.org/how_to_encourage_someone_who_is_stressed_with_work.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/lofese/vejugut.pdfIn PDF document text
    • http://giwuvupajot.epizy.com/logical_and_analytical_reasoning_questions_for_class_6.pdfIn PDF document text
    • https://s3.amazonaws.com/fonibinaraj/explanation_text_features_worksheet.pdfIn PDF document text
    • https://3682d434-6e27-4ac8-9ac2-d3ec24fa429c.filesusr.com/ugd/9b5f63_64bc10e47b7b48adb7ca4735fff6f1e3.pdf?index=trueIn PDF document text
    • https://724418e0-3ace-43c1-abd8-628b4820fc71.filesusr.com/ugd/6df952_9a63dd03ca5641918986b20773b239ab.pdf?index=trueIn PDF document text
    • https://0621cc9e-6449-4e8a-a8bd-baee9ad62a2c.filesusr.com/ugd/affb4a_c2d6e8a8e5c8451d85ab04e590d99ebc.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/midipes/4712688126.pdfIn PDF document text
    • https://s3.amazonaws.com/gofiguj/mabamomerimugokufefuvikop.pdfIn PDF document text
    • http://kidajovude.epizy.com/aaron_shepard_winston_salem_nc.pdfIn PDF document text
    • https://75a697d3-84f0-44cf-bab9-f05e37020c50.filesusr.com/ugd/7c3584_7fcbaceb1b264088a77ef2740134c133.pdf?index=trueIn PDF document text
    • https://df1882fa-13c5-42f1-8438-577935b594b9.filesusr.com/ugd/91932b_ea79f449ea47494c8a6b3a2b66ec07a6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/ganubifirigevi/73836262420.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_off0000e5c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C7 5364 bytes
SHA-256: 803ec0fecc62a03eff1e56f2ab741bb95ad9c7f49bbee934cd4e6cc261f003a6
font_01_sfnt_off0000f7ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7FF 13036 bytes
SHA-256: fb9fcef73af2d922cd2d1d750e3d350d3c7ef4976544f7e9ed99283ded019128