Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f3c4f9cdc60b5f6…

MALICIOUS

PDF

72.7 KB Created: 2021-03-29 19:00:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 137e9e95956ac9abf613a89a1c8791e0 SHA-1: c136cd5ba2da62b8dad547249966e57ec5252302 SHA-256: 8f3c4f9cdc60b5f6706a6e0fcd7b015d53e92578ac979b83432ab56a35d04990
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 a link farm designed to distribute malware or facilitate phishing. The ClamAV detection and ML classifier strongly indicate malicious intent. The embedded URL and the document body, which mentions a school bell schedule, suggest a lure to direct users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://ponafet.ru/wix?keyword=savage+middle+school+bell+schedule PDF link annotation
    • http://cloudmarket.website/kekidapumanigee0bmx.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415055/normal_6042cce2033a0.pdfIn PDF document text
    • https://bewirupudafa.weebly.com/uploads/1/3/1/6/131607000/zofaze_tekebozerubize_nazowi.pdfIn PDF document text
    • http://alteramaks.world/6795310402nvzw0.pdfIn PDF document text
    • http://servisvds.ru/fukafukunujaxuperadalass098.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4443610/normal_60344aca93c99.pdfIn PDF document text
    • https://waxovidimised.weebly.com/uploads/1/3/4/4/134446407/e49f87515f7581.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468259/normal_605a2e15552d3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405206/normal_600fafce6692f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491164/normal_60397d2b22665.pdfIn PDF document text
    • http://idealslimitaly-official.site/texas_principles_of_real_estate_1_bookxq4pa.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382190/normal_5ffcf5067d6e6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414495/normal_6045a1f0ce463.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365653/normal_601250f28d656.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/woneketelak/28657094252.pdfIn PDF document text
    • https://s3.amazonaws.com/sixolose/xeguxodimolapez.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9545e550-5b05-445b-bd43-f4e0227f1598/sistemas_de_manufactura_libro.pdfIn PDF document text
    • https://s3.amazonaws.com/donarepemi/6149413242.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0aad0daf-0ab4-4991-917b-d2d193815af6/john_grisham_books_list.pdfIn PDF document text
    • https://s3.amazonaws.com/tesotiwapax/kawesebebotif.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c6aa5365-66ca-44d9-9bc4-2524bf1b2237/give_me_liberty_chapter_13_notes.pdfIn PDF document text
    • https://s3.amazonaws.com/najubu/borderlands_2_level_50_characters.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_off0000de05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE05 5560 bytes
SHA-256: c848e7e258b1a00b6ef0424a6a9da6086a4802a24af3d1f32ff1a0ede656766b
font_01_sfnt_off0000f0d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D3 10552 bytes
SHA-256: 468eea818f9ad963861c38adcbf19c453ed22a4d698c18dade44a96c7c05d3bc