Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4cff8ee8e59b55…

MALICIOUS

PDF

77.0 KB Created: 2021-04-21 10:01:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 8b68840701264b28e974eb06721e6c4b SHA-1: 49d3adfdd010ca6eca5db00005470fad55be47af SHA-256: 8d4cff8ee8e59b5561353cf38bb9bacfaf95de9999ddc313c9663708006721f9
126 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a link farm, suggesting a tactic to manipulate search engine results or redirect users to potentially malicious content. The ML classifier strongly indicated maliciousness, and the presence of embedded URLs further supports this assessment. No scripts were extracted, but the structure and numerous external links point towards a phishing or content redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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/strik?utm_term=how+long+should+i+practice+violin PDF link annotation
    • https://cdn.sqhk.co/tazofexoz/gigh4jc/wifi_password_recovery_pro_2020_apk.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419827/normal_604195839540a.pdfIn PDF document text
    • https://jolibudowuw.weebly.com/uploads/1/3/4/5/134596284/sugemebu.pdfIn PDF document text
    • https://nimafomu.weebly.com/uploads/1/3/2/7/132710507/tobojinededeni.pdfIn PDF document text
    • https://xomarexisu.weebly.com/uploads/1/3/4/7/134701616/1469508.pdfIn PDF document text
    • https://tovamegudisolos.weebly.com/uploads/1/3/1/4/131411857/9153242.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465545/normal_5fe1960fb154f.pdfIn PDF document text
    • https://cdn.sqhk.co/guzufaseba/p9hiibZ/geometry_dash_2._2_date_de_sortie.pdfIn PDF document text
    • https://sadebisoj.weebly.com/uploads/1/3/2/3/132302749/fe206d7488a.pdfIn PDF document text
    • https://wilowukodol.weebly.com/uploads/1/3/4/8/134881933/sifurojaxu-mokurosib-pawozilixa.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4497370/normal_5fe5c181ac76c.pdfIn PDF document text
    • https://befepoli.weebly.com/uploads/1/3/4/6/134687110/lizagudogimuvumoro.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4401994/normal_60583cce1e58e.pdfIn PDF document text
    • https://xonutupusuvulin.weebly.com/uploads/1/3/1/8/131871786/meletodeleva.pdfIn PDF document text
    • https://govobozof.weebly.com/uploads/1/3/5/3/135315692/e63f4013e3.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://3d5b2cfc-74f5-4c02-8466-0d369b02955c.filesusr.com/ugd/69b86f_868bff8a67d54eebb5da8875fab3ed54.pdf?index=trueIn PDF document text
    • https://3ae4d138-4ba3-4962-98fb-1b98b40a6a82.filesusr.com/ugd/38062a_533de4198f244c90b40748428545b93e.pdf?index=trueIn PDF document text
    • https://4ac36a2f-1533-488b-b282-cf34cdace458.filesusr.com/ugd/bcfc12_170c72844c054cd2a2372baffff2b4ce.pdf?index=trueIn PDF document text
    • https://793776f3-68b4-44d3-947a-596ce2c6f652.filesusr.com/ugd/4e977a_7f817200049b44849908a327757b4535.pdf?index=trueIn PDF document text
    • https://535a9070-e28a-464b-adc5-c02ad08be00b.filesusr.com/ugd/9df9d6_62e83a168e254c359ca84ab4c6623f9f.pdf?index=trueIn PDF document text
    • https://cb47f074-0476-4434-b381-5672a365cab8.filesusr.com/ugd/c46c8a_fbea27485ffd4916986009814eec3afa.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_off0000eefa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEFA 5448 bytes
SHA-256: 961ce2ad08106b6540fe0f664b2b3401e9cee046edf1e7cc3b0bb65b2ded1037
font_01_sfnt_off00010195.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10195 11016 bytes
SHA-256: b652efc384361c075fabea2acca9852522597f78e5101094207b5c3f12c19eb2