Malicious PDF — malware analysis report

Static analysis result for SHA-256 356f55b6dbbe1378…

MALICIOUS

PDF

70.2 KB Created: 2021-09-28 19:15:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 758cefb13a67543e233a9ba6a8e7e3c6 SHA-1: 554fed9a5e82c3079a3e27762c6e29c814ea11bc SHA-256: 356f55b6dbbe137816ca5d3f8d83d8ab189e559d5711363761d74ed67020569f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute malicious content or facilitate phishing. The presence of external URI heuristics and the overall structure point towards an attempt to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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://philabc.ru/uplcv?utm_term=subway+surfers+pc+game PDF link annotation
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614c7132d1cb0---limapikuzinupejipem.pdfIn PDF document text
    • http://odessawa.com/userfiles/file/8385918723.pdfIn PDF document text
    • http://lawfirm.vn/MINH/user_files/file/zizevajovumeveval.pdfIn PDF document text
    • http://boilerservis.ru/uploads/files/terifarimereveriraxelulus.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/ea116be0736d9085c821e017efb080c8/84337144955.pdfIn PDF document text
    • https://kermanrooz.com/img/files/tifilowafurufesalisaziwe.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/161354244cab5e---18889603304.pdfIn PDF document text
    • https://uclerbaklava.com/resources/file/jerazi.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ed9bfdf00b---vejokijetodewiv.pdfIn PDF document text
    • http://smsalumni1971.com/apadmin/uploads/userfiles/files/bijikitobo.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/runolumawu.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/rafanabego.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/7f5af7409aeaea76c564f82cf7527265/lufotemapi.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1632327993.pdfIn PDF document text
    • http://archinfo.ru/uploads/file/38350121773.pdfIn PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/todozozideduge.pdfIn PDF document text
    • http://younewstoday.com/task/userimages/file/dotidazemidepumesoludaz.pdfIn PDF document text
    • https://zaragozadenoche.es/upload/files/fofax.pdfIn PDF document text
    • https://laplacedesstores.com/upload/file/8039010962.pdfIn PDF document text
    • http://simpelms.nl/userfiles/files/mugorazulofawavel.pdfIn PDF document text
    • http://vaynhe.com/upload/files/14883157129.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16143da971105b---tijalurijib.pdfIn PDF document text
    • http://kelkenaghshband.com/app/webroot/img/files/93057722840.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631574418.pdfIn PDF document text
    • http://markaz-e-durood.com/EditorImages/file/41537575277.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_off0000b4ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCC3 10880 bytes
SHA-256: f85eaa8b26ab6125f5b70055d9e4f730ca66c5a62c8e0890bb0d5b92dd069c8e
font_02_sfnt_off0000e5d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D4 14776 bytes
SHA-256: de4cc2ec6cdf4f355e41ef30e270badee1029aa9c8fba6e36b1256444799ca22