Malicious PDF — malware analysis report

Static analysis result for SHA-256 c518cb73005d005e…

MALICIOUS

PDF

81.9 KB Created: 2021-03-26 09:05:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-13
MD5: d67cbb1ddfd9915ac0442792a2609cd7 SHA-1: 6cd103dfa4b00578437b7e763803c8e1f0e9aec9 SHA-256: c518cb73005d005e6c6f3030b9bda5d0fc1ab3c750f96d09f88ef29590ccda80
186 Risk Score

Malware Insights

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

The sample is a PDF document that contains a large number of external links, many hosted on disposable domains, characteristic of a link farm or SEO scam. The document body, though heavily obfuscated, suggests a lure related to 'simple harmonic motion answer key'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://vilenefex.ru/wix?keyword=simple+harmonic+motion+answer+key PDF link annotation
    • https://cdn.sqhk.co/metusoteliza/g4hh6Yd/spectrum_analyzer_app.pdfIn PDF document text
    • https://cdn.sqhk.co/xoguvamev/TAgREjg/zombie_outbreak_response_team_wiki.pdfIn PDF document text
    • https://cdn.sqhk.co/bexefoboxevi/gi0km3P/fevinuxemovetonovokixu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382948/normal_60146c8c6ee55.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419818/normal_5fe8bd0f38746.pdfIn PDF document text
    • https://cdn.sqhk.co/kirovuwuvo/WhghdjW/arabic_ringtones_for_iphone.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427526/normal_5fffb587015dd.pdfIn PDF document text
    • https://cdn.sqhk.co/sozodumupof/hEHEhf6/whatsapp_tik_tok_video_download_2020_mp4_free.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4493867/normal_5fec053bc7c12.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/pajukovuxetu/free_english_worksheets_grade_6.pdfIn PDF document text
    • https://63150c49-9e7f-4923-bc7a-1e4049050ce6.filesusr.com/ugd/cba449_18e1daca273848828990aa387f072b90.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ad428dba-0546-4adb-9a7b-286c7fc56545/80818553789.pdfIn PDF document text
    • https://s3.amazonaws.com/xoguwavosuje/learn_french_book_free.pdfIn PDF document text
    • https://c84d532c-3b33-47d6-96aa-4134a1164eb1.filesusr.com/ugd/6d45f6_5993c4ed23e149008b5ce7f7b6e9f712.pdf?index=trueIn PDF document text
    • https://17c3d818-7f64-4152-976a-2fa997d7a7be.filesusr.com/ugd/e2c250_4ea870f9f5f34268a27a9b92bcd75bd9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9ed133d-39cf-42ce-8958-dc322af569b6/whirlpool_front_load_washer_cleaning_cycle.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3be04bf5-f002-4ecc-8bba-decf94214e21/100_g_harina_en_tazas.pdfIn PDF document text
    • https://s3.amazonaws.com/satulibaren/minimalist_logo_design_template.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b573c954-d020-4e63-bb58-c77140af3cd0/brian_tracy_eat_that_frog_quotes.pdfIn PDF document text
    • https://s3.amazonaws.com/wanalovum/bonacci_editore.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2EF 5320 bytes
SHA-256: 05d5304f03d9c1e96edb20631ba304fd89657a9fa6946ce212857a57dcf021bf
font_01_sfnt_off000104db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104DB 11440 bytes
SHA-256: 90c96acec18936187510c0c7dc22cb932ff2837a66a8b0e094abb27ddfd9b73f
font_02_sfnt_off00012bf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BF2 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230