Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a03393707180530…

MALICIOUS

PDF

75.1 KB Created: 2021-05-22 16:40:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: e250a554e41bebc55be128a0aa9794be SHA-1: dda531a0961fd80ac6078f4828bc851650523c2d SHA-256: 8a0339370718053043df645df4e24fca2b9a6c0926232527ca00f79ea80441d3
246 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses brand-impersonation credential phishing. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Brand-impersonation credential phishing lure critical SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: action link to abused redirector https://fefosixofenovi.weebly.com/uploads/1/3/4/7/134755919/wonibumepexut-lexox.pdf.
  • 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://zajinet.ru/strik?utm_term=does+microsoft+offer+excel+certification PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4417318/normal_6063174805a70.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4476566/normal_5fe391c9eb148.pdfIn PDF document text
    • https://fefosixofenovi.weebly.com/uploads/1/3/4/7/134755919/wonibumepexut-lexox.pdfIn PDF document text
    • https://rotarivinevi.weebly.com/uploads/1/3/4/5/134599250/nutidebibilul-kakebikewapos-kupuxifuda.pdfIn PDF document text
    • https://rapelolizoxofi.weebly.com/uploads/1/3/1/3/131381924/gikalalefabegazule.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468536/normal_5fd385ef430d7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426572/normal_603a1f8885de9.pdfIn PDF document text
    • https://buritozube.weebly.com/uploads/1/3/0/7/130775753/makajusitesagise.pdfIn PDF document text
    • https://jusatupu.weebly.com/uploads/1/3/4/6/134652681/3813349.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/fd6212e8-c6ba-47b1-a719-cb5c2f662823/xiseguraf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a7327152-ccc2-4fe7-85a2-771f7825486c/xefutiforitekotidexok.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c3b6d19c-9521-4410-b793-0390f5b0a25c/what_does_supplanter_mean_in_hebrew.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c8aa4c99-04fc-4b0b-9eb9-df4280381a2c/what_are_the_components_of_mis.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/700bb6aa-6844-455c-bcc4-6c627a633eae/linear_graphs_worksheet_year_8.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b488f7af-14b7-422b-9186-33b48a8be04c/bufeluzeremulufumovenobeg.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/433349d2-21f7-4ea1-8cd8-d65a4e1a1fd8/1689_baptist_confession_of_faith_tagalog.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/138bb9e7-7884-4d04-bf41-11c87f9352be/51397010042.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9964431-63a0-4851-8463-3f60ca466a3b/zubizefuvu.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_off0000e65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65E 5096 bytes
SHA-256: 6761dc37715d9cbea150948b1c8972cf95935b6bc566868c9f01b5711d5669ec
font_01_sfnt_off0000f7a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A6 11716 bytes
SHA-256: ffe936d720ebb708eba824ed640ece5a7beafca278bc2f873ec3229dbf4d753c