Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae3ec7cc4ff731c8…

MALICIOUS

PDF

85.6 KB Created: 2021-09-14 11:05:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 222252ba659b321b74bc5e57ef666b8e SHA-1: 4ae897889622bd5e83b8ce6f42cd4c9f108d766b SHA-256: ae3ec7cc4ff731c83e554fee674a10b53894fd3d8d6b4515b3642a567cd9f87c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and embedded URLs suggest an attempt to lure users to malicious content, likely via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://nguyenhungstone.com/uploads/image/files/zewaruzufu.pdf In PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/furorugofokowakeja.pdfIn PDF document text
    • http://tion.hu/upload/file/xebikumujaxuzad.pdfIn PDF document text
    • http://casinodanmarkjackpot.dk/userfiles/file/15806446401.pdfIn PDF document text
    • http://suarezbeltran.com/aym_images/files/77084104712.pdfIn PDF document text
    • http://dochoiotovn.com/uploads/userfiles/file/43265602360.pdfIn PDF document text
    • http://srub-servis.ru/userfiles/file/dutiwopifokile.pdfIn PDF document text
    • http://galaxyjewel.cn/uploadfile/files/norosoneluteronidopigot.pdfIn PDF document text
    • http://ferrogep99.hu/static/media/file/sifuzovufarokukunomu.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcb6af4140---fokipe.pdfIn PDF document text
    • http://tdjl.com/uploadfile/file///2021090507534340.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/12749192520.pdfIn PDF document text
    • https://sakura-bashi.com/uploads/files/202109121936006369.pdfIn PDF document text
    • http://broadgatecapital.com/userfiles/file/26975180914.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd7142caa2---gitipepo.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/61787998283.pdfIn PDF document text
    • https://www.douggoodkin.com/admin/ckfinder/userfiles/files/70965695861.pdfIn PDF document text
    • http://apple888.vn/luutru/files/pokojorugazemibu.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/f101lmm6mreijb3il2pss07n76/11210222412.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613498e3ad38e---53418981000.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/48857235330.pdfIn PDF document text
    • https://smwebtechnology.com/arishayurveda.com/userfiles/file/90464803211.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/3d648622212eb569f475bcc625e102f4/66018008250.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=best+android+offline+games+2020PDF link annotation
    • 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_off0000ec61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010478.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10478 10992 bytes
SHA-256: 91ed4b54bb234fe3bb9ff8fa468bc234a68f2058e43af4c214968767f25e17b7
font_02_sfnt_off00011ddb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DDB 16808 bytes
SHA-256: aad859b8c8b6ddb384bc666fad1497798d081718ac53378b814e22625fa37566