Malicious PDF — malware analysis report

Static analysis result for SHA-256 51574cdec24b67cb…

MALICIOUS

PDF

112.2 KB Created: 2021-04-06 10:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: e8df20ceaa3a9ad34557c57029ed9972 SHA-1: dbce5cdca77eb9c36f51cc35fda31799ba4cebc8 SHA-256: 51574cdec24b67cb90e15fb1228100489287ef4714cbfbaee52a4eba2adec958
126 Risk Score

Malware Insights

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

The PDF file contains embedded URLs and heuristic detections indicating it is a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains text related to 'Toeic reading answer sheet pdf', which is likely a pretext to drive users to the malicious URL.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://jumiwimov.ru/award?keyword=toeic+reading+answer+sheet+pdf PDF link annotation
    • http://nawitebexu.medianewsonline.com/79407333009.pdfIn PDF document text
    • https://jatazuleb.weebly.com/uploads/1/3/4/6/134662889/7581706.pdfIn PDF document text
    • http://sunazeremitiwu.mypressonline.com/veduluro.pdfIn PDF document text
    • http://gubuxuk.scienceontheweb.net/how_to_use_innova_obd2_scanner.pdfIn PDF document text
    • https://jepejopik.weebly.com/uploads/1/3/4/6/134610321/899732dc3590749.pdfIn PDF document text
    • http://witikotuxigere.scienceontheweb.net/nadagujedogesakeba.pdfIn PDF document text
    • https://lidugozomamaxo.weebly.com/uploads/1/3/1/6/131606349/98891406203.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/485ae4bb-4f68-4bb9-b07e-28692026b00f/mutaridora.pdfIn PDF document text
    • https://s3.amazonaws.com/lomiwexuva/the_angriest_man_in_brooklyn_parents_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/jebokizez/jokemobafimidika.pdfIn PDF document text
    • http://zatuvejamubolo.atwebpages.com/tibubos.pdfIn PDF document text
    • http://sinusudixuxuwad.atwebpages.com/31948474305.pdfIn PDF document text
    • http://domebiwek.myartsonline.com/peludidovug.pdfIn PDF document text
    • http://jusopetikikij.onlinewebshop.net/dowopi.pdfIn PDF document text
    • http://sewujajapivix.onlinewebshop.net/how_to_read_poem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/982c88a1-f635-49c1-8459-9ff82a807177/69794498102.pdfIn PDF document text
    • http://zikoliduxa.atwebpages.com/33937377674.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/13a813e7-0441-417e-b47d-6456b5bab971/ponarifi.pdfIn PDF document text
    • https://s3.amazonaws.com/waxapoz/make_cv_online_free.pdfIn PDF document text
    • http://vujijemu.atwebpages.com/bepupenoluxewarepiliregur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cf54ab0c-9fb0-49e1-9bf8-8ab9d2ebae22/towafasemijag.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn 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 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013a45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A45 6424 bytes
SHA-256: 50759c40df67ec181331d37bc16259f4db20c39507a2c7d18444f96545433770
font_01_sfnt_off000149f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149F4 5636 bytes
SHA-256: 383e934c69e6b222a1e5caedcf15c90b494cae29875594f683238cb0bbf0fb1f
font_02_sfnt_off0001592f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1592F 5428 bytes
SHA-256: e143c10a0088f7d50e38fb609335a0afb0780439c23c050eb215e15fba5a1691
font_03_sfnt_off00016bad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16BAD 2148 bytes
SHA-256: 0578ce2a22ac6fea9c93768ba3c906d822ed7a723a9c558bcfebd77a500b9a46
font_04_sfnt_off000175c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x175C4 10940 bytes
SHA-256: feba0b2ee698a40323ce166812474e7182387a7f89cab76af228595286e6c7d0
font_05_sfnt_off00019b2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19B2E 16140 bytes
SHA-256: 1ffca1ef16be5e2ec436e77f9211a88ad3199dc781cb76600401cc2e2c7dce6d