Malicious PDF — malware analysis report

Static analysis result for SHA-256 f851c4e2fdd51c87…

MALICIOUS

PDF

79.7 KB Created: 2021-06-01 07:04:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: a544f6c597bf505f1351ec1d6fab9b5b SHA-1: 94932462a80ad466f63b324b28a0b2dee079cb07 SHA-256: f851c4e2fdd51c870533343771db34c14a0288a4852ee570f3c37e1ed3e8524a
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 pointing to disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. While no scripts were explicitly extracted, the presence of numerous embedded URLs and the heuristic firings point towards a malicious document designed to redirect users to potentially harmful sites.

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://queure.ru/pbw?utm_term=sims+freeplay+money+cheat+android PDF link annotation
    • https://losiweso.weebly.com/uploads/1/3/1/3/131380476/b3c3f621a.pdfIn PDF document text
    • https://jumopafebog.weebly.com/uploads/1/3/4/5/134504074/zirovurikaf_sasejonik.pdfIn PDF document text
    • https://vumerajijo.weebly.com/uploads/1/3/2/8/132815742/805daff.pdfIn PDF document text
    • https://vakilonote.weebly.com/uploads/1/3/1/3/131382032/gumegoz.pdfIn PDF document text
    • https://jokasagumejede.weebly.com/uploads/1/3/1/0/131070006/9373165.pdfIn PDF document text
    • https://wuxelulomevadi.weebly.com/uploads/1/3/4/9/134904547/rekireroligitinixe.pdfIn PDF document text
    • https://pebizadovabunal.weebly.com/uploads/1/3/4/7/134711288/daseva.pdfIn PDF document text
    • https://gawajofanobovap.weebly.com/uploads/1/3/5/2/135296378/fababam.pdfIn PDF document text
    • https://zajoxewamabovi.weebly.com/uploads/1/3/7/5/137503144/powezika_rigonikesubeda_bumukiduv_paperazaruk.pdfIn PDF document text
    • https://papuwupiruji.weebly.com/uploads/1/3/4/3/134348025/2254489.pdfIn PDF document text
    • https://semufukat.weebly.com/uploads/1/3/1/8/131857602/fuzepewi.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/f81f578c-b397-470f-b794-38cb77a504d4/kefopenikujefakimakowaz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/717f4d46-f749-4b0a-9a27-7fb02017ee59/esercizi_svolti_nomenclatura_chimica_organica_zanichelli.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8e0803fd-9074-4247-a214-650312e650d7/how_much_money_does_prince_harry_worth.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb32cb17-53b2-42f8-b8f6-2c9ad00be2a1/rupizawemunikajuwat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3eced27e-44a4-4a6c-a724-819a0a581df3/how_to_program_directv_remote_with_samsung_smart_tv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f8d818d-d567-4b48-b95f-d8fe0b4d38bc/ravota.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15031e96-a641-4c0a-9fbf-53a2a2b3da9a/tasujebare.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8d67a21e-6ac8-4883-8586-ee4f70118579/nursing_herbal_medicine_handbook.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/263ec8cc-4e5b-4e36-ae5e-bc0e9abca697/dopudetufozuri.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9aa0646e-f703-46bb-bec5-66410b967954/encyclopedia_brown_box_set_4_books.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_off0000f885.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF885 5600 bytes
SHA-256: efe413582a27046fb7d433eab48cbe6ba0863672ea65e9522b37b7b0bf637e35
font_01_sfnt_off00010b6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6A 10752 bytes
SHA-256: acde6c1ef01555bdf78755ff982e0eb6252c65ec0f0f734988498267641f66ad