Malicious PDF — malware analysis report

Static analysis result for SHA-256 af643ed60313685a…

MALICIOUS

PDF

80.2 KB Created: 2021-09-18 02:44:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3efe7e0c35691ddf529dc1df50f1a42b SHA-1: 71a8c13f48bfc0aca9a72773039103cdd02532a5 SHA-256: af643ed60313685a7ee430fc28e8ba6373db59c30e8c72830c44cc85ba13e0bd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to compromised CMS uploads and disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the heuristics suggest it's part of a link farm strategy. No scripts were extracted, but the overall structure and URL distribution are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://crysiq.ru/uplcv?utm_term=inspiring+h+words PDF link annotation
    • http://naso10.com/userData/board/file/lorubi.pdfIn PDF document text
    • http://galenbio.com/images/upload/file/dumoxepisirifevemu.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1614211163073c---85605389269.pdfIn PDF document text
    • http://ankaraeksioglu.com/resimler/files/fomekevapanimuvumunibid.pdfIn PDF document text
    • https://xn--90aoja6ahg5ds.xn--p1ai/uploads/files/zugoba.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe5b469b0b---lubaxemozadus.pdfIn PDF document text
    • http://thaisomboonautopart.com/userfiles/files/wowuba.pdfIn PDF document text
    • http://sakuragiramenandsushi.com/uploads/files/76896246615.pdfIn PDF document text
    • https://srccaa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/tivipigupekixibovifipi.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/4016159942.pdfIn PDF document text
    • https://sergeca.com.ve/ckfinder/userfiles/files/minubokomo.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/mujidisali.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/88179400095.pdfIn PDF document text
    • https://wendi101.com/userfiles/file/nasanogiwixob.pdfIn PDF document text
    • https://solelane.com/ckfinder/userfiles/files/77816554168.pdfIn PDF document text
    • http://flagrant-desir.com/userfiles/file/nuzevufum.pdfIn PDF document text
    • http://domuran.pl/files/file/9183535043.pdfIn PDF document text
    • https://etimes.mn/uploads/files/96933109947.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013new/admindia/ckfinder/userfiles/files/petunebeseji.pdfIn PDF document text
    • http://fiumaradelsossio.it/userfiles/files/36962803215.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/91175519832.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/dijoboxelubunifo.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137877abef7e---14181654537.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210912_194624.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E7 10268 bytes
SHA-256: b881f76bde87d2331bcd0057c8dd29bef81c889643e9adde9df68fb2ed71cd54
font_01_sfnt_off0000edae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105C0 17704 bytes
SHA-256: 1989f632804287fd4c419bf1fab16db56b238b7ad6b6fe0f792ac1ec1ae65836