Malicious PDF — malware analysis report

Static analysis result for SHA-256 e404cfbc733db2bc…

MALICIOUS

PDF

70.0 KB Created: 2021-09-26 10:13:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f9da20fcd7253f906ec9f17a5bf42adb SHA-1: 4736d05ccb20aeebfc0214032b14a7147124cce4 SHA-256: e404cfbc733db2bc15abfc909d5a8b7d27929eb7c208179bfcdd869ff556a1fc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs, many of which point to external sites hosted on compromised CMS platforms or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings clearly point to a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://phukienbep.net/media/files/19438739457.pdf In PDF document text
    • http://cudicio.it/images/file/95508258242.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/20141455916.pdfIn PDF document text
    • http://dorapeyzaj.com/userfiles/file/71705116741.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/511c41f9800ca82ffde15dabfad8c507/mumutevasego.pdfIn PDF document text
    • https://lmcmanager.com/ckfinder/userfiles/files/xolopinomidowerudine.pdfIn PDF document text
    • http://zjnep.com/ckeditor/ckfinder/userfiles/files/40699363302.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/nelamujirut.pdfIn PDF document text
    • http://barcelonahotel.vn/UpLoadFile/file/foguninupuriro.pdfIn PDF document text
    • http://makesomenoise.hu/upload/file/nugukatalovopu.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/881a59180fd4471cc43c7ea6b65960d9/95958398077.pdfIn PDF document text
    • https://www.aspart.ro/ckfinder/userfiles/files/kazodiwejepu.pdfIn PDF document text
    • https://hoangmailogistics.com/asset/site/files/jibevitidijapuverujefajuz.pdfIn PDF document text
    • http://sissonne.hu/editor_up/vokenesoxareboviduzibul.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136745f07922---sereni.pdfIn PDF document text
    • http://dreamsurgerycn.com/ckupload/files/67762576615.pdfIn PDF document text
    • http://grabnerestriche.at/mameminovibijowotuwe.pdfIn PDF document text
    • https://cherrychile.cl/cherry/uploads/contenido/files/nesoxupafivi.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fed600e56d---parovumotorigaxaroro.pdfIn PDF document text
    • https://apapunada.com/contents/files/xukofofisesobagefiw.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/93641221261.pdfIn PDF document text
    • http://aftp.bg/userfiles/file/tusenid.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/984cdb712bb65023e186aafaaa7971e2/ratogetisu.pdfIn PDF document text
    • http://pro-customer.de/userfiles/file/gejusenajujalevedu.pdfIn PDF document text
    • https://szelvedojavitasmiskolc.hu/files/files/rotilorupexepageraxukeze.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/62051134390.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=android+studio+screen+recorderPDF 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_off0000b559.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB559 14980 bytes
SHA-256: e8a2e9f195cd3e9bd6366495935e35333070d759d7dfd66073494d47f2c4e636
font_01_sfnt_off0000db03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF31A 10236 bytes
SHA-256: ec441ec76b203d20b9521c944f854c18e43b220286ec7eea80ae0cdb79fc32aa