Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad91913a58b3846e…

MALICIOUS

PDF

86.4 KB Created: 2021-03-26 07:23:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 85e796aa723be9b4ef0f8185bdf6bd5f SHA-1: 816310fb0d7c7d45137b723315bb7c89ab1339a3 SHA-256: ad91913a58b3846e2885cde01e8ec479f19699b0118d9cfa5098d373611946ae
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable hosting, and is flagged by ML classifiers and ClamAV as malicious phishing content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a link farm, likely to distribute malicious content or phish for credentials. The document body, though heavily corrupted, suggests a lure related to a 'genetics worksheet'. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://xezojetit.ru/wix?keyword=using+probability+in+genetics+worksheet PDF link annotation
    • http://smirnoff-optic.com/refozimalzfq6.pdfIn PDF document text
    • https://cdn.sqhk.co/fuwufupi/ibhmhhR/burgerology_patchogue_brunch_menu.pdfIn PDF document text
    • http://instup.xyz/brat_diet_patient_handout2lma9.pdfIn PDF document text
    • https://cdn.sqhk.co/wijelukifap/fpAgf1T/modul_praktikum_biologi_sma_kelas_xii.pdfIn PDF document text
    • https://cdn.sqhk.co/jofijoju/CA2HjcV/44578310476.pdfIn PDF document text
    • http://jakor.pro/motorola_mc5590_drivervj7b4.pdfIn PDF document text
    • https://cdn.sqhk.co/nebafori/Fvsmljb/dune_battle_planes.pdfIn PDF document text
    • http://chestlune.online/true_colors_assessment_freezp0j3.pdfIn PDF document text
    • http://ezfix.asia/9801068269936bon.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e4fb9bf1-a3d6-4767-9bf2-2a1021e5dc09.filesusr.com/ugd/53cfc7_299532db1acc4ef98ad1a4189e6d8b32.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zalomi/online_unzip_files_free.pdfIn PDF document text
    • https://a3de454e-1598-42bb-a259-4eb69c42f179.filesusr.com/ugd/fb5067_93b52e2baa2d48ce9208f7521284fdeb.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vitelitubovuluj/cavatina_myers_sheet_music.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7e0b1d74-5c91-43ea-b7d8-b23c8d66ab57/my_system_aron_nimzowitsch_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/75df0a4a-3e09-425c-8d93-39b0225bb9f3/girl_killed_in_st_elizabeth_jamaica.pdfIn PDF document text
    • https://s3.amazonaws.com/pugomonapoxuxe/mawedajejuziniwenogunifi.pdfIn PDF document text
    • https://51bf459c-6b46-41b0-863f-532cf8a77e0d.filesusr.com/ugd/2eedf1_1e264071079d4f3bbfe8728a0c95f981.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/topipovikapari/what_is_my_sun_sign_in_vedic_astrology.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32c0972d-a31d-4bbd-a0cb-5de6d604f4af/nivopolipojare.pdfIn PDF document text
    • https://c0cead0d-5248-483d-940e-95cc3acd9bde.filesusr.com/ugd/20d83a_c93d240067d948ef97090842ef4ddbfb.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zobuwubedak/anti_malwarebytes_free.pdfIn PDF document text
    • https://b0c090b1-cb02-46d8-8a69-3fb9d82636b6.filesusr.com/ugd/4dbf3f_473cb64ed7ff499489cc4a03a16b8e45.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_off00011209.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11209 5584 bytes
SHA-256: 1b418d99fe8d5e71e6f038b879f620f0035b8b30f941babcc96a5a6f74f086cc
font_01_sfnt_off00012517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12517 11372 bytes
SHA-256: ba701702d70d3c1429815482cc66adf2c6d24ebb931005c07cfe50afdcc1b094