Malicious PDF — malware analysis report

Static analysis result for SHA-256 425bdc36877f0239…

MALICIOUS

PDF

118.0 KB Created: 2021-09-04 01:18:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: c74de40d0b8066e1f95c83b7572b7d1b SHA-1: 18d96f31927518a9784ab85ec577d326222e8068 SHA-256: 425bdc36877f0239a96a8c6b501cfa849491f2ba13eb324a1a2f3bf2b60ee62b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites and disposable domains. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is designed as a link farm to distribute malicious content or phish users. No scripts were extracted, but the URL structure and heuristic findings are sufficient to assess its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://coretry.ru/uplcv?utm_term=back+on+the+chain+gang+tab+pdf PDF link annotation
    • http://angelofthewinds.org/ckfinder/userfiles/files/xutubegagulujubowaba.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/84us5fvjjikjt106tpi0cmltek/52008984602.pdfIn PDF document text
    • https://alev.az/userfiles/file/jijolopejurumekezemegu.pdfIn PDF document text
    • https://megatekspb.ru/sites/default/files/uploads/lumelorilep.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608687d8290ac---92543564985.pdfIn PDF document text
    • http://beloit1962.com/clients/8/83/8368a4f838dea3176655029ae9e337da/File/46904505572.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/460d7cb1d1c84c7d16f1ff602c846497/88134533559.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/d79561a58be31b2e861d4c799caee2a0/zogexigezamabajuj.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16105b5df68c9c---26046043312.pdfIn PDF document text
    • http://srub-servis.ru/userfiles/file/86311190593.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/bolavoveg.pdfIn PDF document text
    • http://fotosvatba.net/userfiles/file/lejatimepaxol.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/7f4cc8eaa2a74744e8811d3583feaa60/xogezazaxut.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/sexexebimetifew.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9831a696db---gulurofexifi.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c98bf578185---wibexukuvafebonu.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/kovatanedomunavomi.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/xisaped.pdfIn PDF document text
    • http://mousike.it/img_ins/files/51133462102.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a10e2f1bb12---sasalalewebako.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/bifagidixosogedaban.pdfIn PDF document text
    • http://yenidenyuzlendirme.com/ckfinder/userfiles/files/jepalabarogipiw.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cecb44d3f04---wipuxefuwepof.pdfIn PDF document text
    • http://briarcliff68.com/clients/71184/File/49402028496.pdfIn PDF document text
    • http://faxik.ru/ckfinder/userfiles/files/84312267074.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_off000166e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x166E8 19180 bytes
SHA-256: bc2cf87758106c392c5b438010d1cc8591b95c89c5c207252ceaa531e788b45e
font_01_sfnt_off000198fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x198FD 10868 bytes
SHA-256: 697a9d260061119481e5b29fda615989ba59faa1d7a0073e9d656db32f1d584e
font_02_sfnt_off0001b1ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B1AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1