Malicious PDF — malware analysis report

Static analysis result for SHA-256 98286f03eacb1536…

MALICIOUS

PDF

85.1 KB Created: 2021-06-11 03:33:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: ffec8c0106aa6445c01dbbd26968e4d4 SHA-1: 5114e2252906531777608769e88b3de02c0ac60c SHA-256: 98286f03eacb153669b4796285f43a65a3359149406efd4d5319deeb40da68d2
126 Risk Score

Malware Insights

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

The PDF document contains numerous embedded links, identified by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic, pointing to various domains. One prominent URL, https://wastran.ru/pbw?utm_term=11+plus+jumbled+sentences+worksheets+pdf, is flagged as suspicious. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://wastran.ru/pbw?utm_term=11+plus+jumbled+sentences+worksheets+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4475734/normal_604b9f56c1425.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408707/normal_5ff16be040e66.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461205/normal_600364bf56df9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465702/normal_603c273208c57.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421627/normal_60c0c03f3aba9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4419204/normal_5ff07985941d8.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4417321/normal_60b58e73afe94.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370543/normal_60611632aaddd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454990/normal_606c13ad5f84f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465269/normal_60c177b7871a3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377116/normal_604cfb7626f0e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494149/normal_604853406ffdf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393197/normal_6062a4e43ad95.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://maxasol.pbworks.com/w/file/fetch/144548331/caracteristicas_de_los_enlaces_covalentes_e_ionicos.pdfIn PDF document text
    • http://fatakalewene.pbworks.com/w/file/fetch/144505308/52721198486.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef79a3be-7d30-4df9-901c-2d5c41df0068/how_to_apply_for_ehsaas_labour_program.pdfIn PDF document text
    • http://wufamazajo.pbworks.com/w/file/fetch/144877149/cessna_172n_parts_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5421e16d-45c4-428c-82c2-fbbdf240465b/does_directv_have_any_music_video_channels.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/be571812-24e3-4746-9ee2-603b19e6a99d/74269276470.pdfIn PDF document text
    • http://rimogeto.pbworks.com/w/file/fetch/144427530/clculo_mental_para_nios_cuarto_primaria.pdfIn PDF document text
    • http://kepojijudiva.pbworks.com/f/what_do_small_frogs_eat_besides_bugs.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eecde78c-378f-471b-9844-cf109d96d7ff/jaybird_x3_charger_australia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8eed484c-5df8-4527-ba6d-336bc3063ed9/58470743626.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/84467d9b-c6bf-455d-9ed0-6613bafececc/how_to_reset_a_toshiba_fire_tv_remote.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f078.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF078 5512 bytes
SHA-256: 38389d30ab2c37798593e89330a101994739a9d2de4a88bd112f00cce32ff1b4
font_01_sfnt_off0001031b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1031B 1800 bytes
SHA-256: 51ebeec29509b87aa858d500e37ac8853184703d07d1f913ce36d8e1dc7764c0
font_02_sfnt_off00010ba9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA9 11152 bytes
SHA-256: 57c6b64e275fd97f0026f599115fdd736c3d6929426ed3fc05ac00b9e58e8640
font_03_sfnt_off0001311a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1311A 16092 bytes
SHA-256: 39b2f4b99ee08965fd4836f89f628a00cde8346cb181131bba0308e80db8fb67