Malicious PDF — malware analysis report

Static analysis result for SHA-256 745248b5fdb9fe96…

MALICIOUS

PDF

78.2 KB Created: 2021-06-04 12:05:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 1a5ecadb4b27254e1233d440604f542f SHA-1: 4a91155fadd92616f287850f6b36531f9cf99ae2 SHA-256: 745248b5fdb9fe96e0bfd869a8c30544b3824cc11f74258b0026911c3d89e23b
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. The heuristics reveal it functions as a link farm, presenting numerous links to other PDF files hosted on various domains, some of which are identified as disposable. The embedded URLs, such as 'https://archism.ru/pbw?utm_term=tharntype+book+1+english+translation+pdf', suggest a lure to download specific content, likely to facilitate further malicious activity or phishing. No scripts were extracted, but the PDF structure itself is used to host and distribute links to other potentially malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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 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://archism.ru/pbw?utm_term=tharntype+book+1+english+translation+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4486748/normal_6021ac6d2157f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407085/normal_6015b9efdc159.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449775/normal_605f4b0cd4b3f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497079/normal_5fdb8545eb6c8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375521/normal_5fff80f36a40d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368955/normal_6028264020dfa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380229/normal_601fcbcb7385c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403117/normal_60600abb9c7be.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368466/normal_605df606bd71b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465402/normal_5fefc5c97c1e8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379973/normal_606bec4540290.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452376/normal_6010f4a4e771f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419628/normal_602be70a1a4ed.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489722/normal_5ff38a6bea253.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nubuzefi.pbworks.com/f/povirinimotaboba.pdfIn PDF document text
    • http://fokopaviwu.pbworks.com/f/xogasug.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6ee7ddd5-d51d-489e-8c8e-4767f3893c4a/bhaja_govindam_video_songs_download.pdfIn PDF document text
    • http://fevuxowina.pbworks.com/w/file/fetch/144535923/sysmex_5_part_hematology_analyzer_price_in_india.pdfIn PDF document text
    • http://wufamazajo.pbworks.com/f/what_is_the_last_date_of_submission_of_ignou_assignment_2021.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f4cfb2b-ece6-4fff-b517-e9daa6f7e440/76129133437.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdadddb7-cfec-4720-97a0-821c52ad4522/69786964383.pdfIn PDF document text
    • http://refarumiba.pbworks.com/w/file/fetch/144581790/how_to_make_barley_tea.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a49fb43-c4ef-460a-a12d-4b115baccb0d/wufafowadotesiru.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_off0000f521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF521 5608 bytes
SHA-256: 4831c97670855f26c570ce67bf15567716db303d9a3f1efd518b60ce3df2475c
font_01_sfnt_off00010836.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10836 10256 bytes
SHA-256: ebdb225ada406f8a1c5deb43f8afcce62fac5df717aec724ce28f158ac0ab5a6