Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1be024eab413758…

MALICIOUS

PDF

75.7 KB Created: 2021-05-25 00:42:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 52e5f83c7ff7fe6a8940e9586aa9bfa0 SHA-1: e93fa3d2d120a14e18a8c74bd106f81633a4954a SHA-256: c1be024eab4137583a23b30ec0ac42faa4f37a4b63b705c47a70c15e720de9e1
286 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF document contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The presence of a fake CAPTCHA and brand impersonation (Facebook) indicates a credential phishing attempt. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 8

  • 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.
  • 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://kimetupuvojum.weebly.com/uploads/1/3/2/6/132680977/janupitasufuramuxes.pdf.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://resalured.ru/strik?utm_term=unimaid+2020+admission+list+pdf PDF link annotation
    • https://kimetupuvojum.weebly.com/uploads/1/3/2/6/132680977/janupitasufuramuxes.pdfIn PDF document text
    • https://dexewagumaz.weebly.com/uploads/1/3/1/4/131438443/3795625.pdfIn PDF document text
    • https://gizunujidibe.weebly.com/uploads/1/3/0/8/130814387/3890044.pdfIn PDF document text
    • https://vixagudidiw.weebly.com/uploads/1/3/0/7/130775505/3753583.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421217/normal_5fd9761e26b0e.pdfIn PDF document text
    • https://fekakawe.weebly.com/uploads/1/3/1/4/131437222/jixamuxavuke.pdfIn PDF document text
    • https://zotorakiv.weebly.com/uploads/1/3/0/7/130739478/610890.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413977/normal_5fe3545e83e1e.pdfIn PDF document text
    • https://nuzepobijane.weebly.com/uploads/1/3/4/8/134885792/datusulidatumuj.pdfIn PDF document text
    • https://dajilifu.weebly.com/uploads/1/3/4/8/134891154/b722cea.pdfIn PDF document text
    • https://wuliwedifa.weebly.com/uploads/1/3/4/7/134753749/nevapafuli-batarusiw-vapufanovojodix.pdfIn PDF document text
    • https://xufiwelak.weebly.com/uploads/1/3/1/1/131164558/zolazubarafama_runinogudipar.pdfIn PDF document text
    • https://tojabefe.weebly.com/uploads/1/3/2/3/132303019/c89a90a2a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4457561/normal_5ff171c7616d1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424935/normal_5ffdf5bf44684.pdfIn PDF document text
    • https://rajikaluniker.weebly.com/uploads/1/3/1/3/131383998/jefijowi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459477/normal_6003d1cee4075.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407085/normal_60669c4ed5f1d.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000eb73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB73 5356 bytes
SHA-256: 323987d03c40e4b390040ec2ccb563eb76ce8144f861acfec6f38733acc767e9
font_01_sfnt_off0000fd9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD9E 10632 bytes
SHA-256: 8e7de834e0b994388c02d7aed4a4266d5a8aad19052e6023035df2f668db3fc8