Malicious PDF — malware analysis report

Static analysis result for SHA-256 558eac43c4e1c1e3…

MALICIOUS

PDF

76.6 KB Created: 2021-10-06 00:58:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 20a0a4f7dc5392dccbb6fc91bbe9bc3a SHA-1: adddc5fd53240992a9c8d106fadc1638da87e229 SHA-256: 558eac43c4e1c1e34b02530f07b5bb756a73785a3f425ed99a8a1b3391c68f96
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Numerous heuristics indicate the PDF acts as a link farm, directing users to various disposable domains and compromised WordPress upload storage, likely for phishing or malware distribution. The presence of external URIs and link farms suggests an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://inwebjor.ru/uplcv?utm_term=how+to+clean+frp PDF link annotation
    • http://mtecommerce.it/public/news/file/pafudifopubuji.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210906151823.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109050301151286.pdfIn PDF document text
    • https://printjet.pl/pliki_user/File/novuza.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/56284472042.pdfIn PDF document text
    • https://kcss.hu/korosi/userfiles/file/xekodamenixexobek.pdfIn PDF document text
    • http://vevo.keresztessyoptika.hu/elemek/file/lujirazexulorufivi.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/fatud.pdfIn PDF document text
    • http://ihdbd.org/upload/files/11179852100.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/file/22032065161.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/8c79e7dafa3a9f26b1189ec17e70c753/ludukuz.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16147e5c945ece---sufoxogarudubexuwoxejar.pdfIn PDF document text
    • https://luxm.pl/userfiles/file/rosuvemawolikenavat.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021921758305902.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/67999352862.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/35357428860.pdfIn PDF document text
    • http://vivatbacchus.hu/files/file/67360091673.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613316a5a45e0---jezatewuxi.pdfIn PDF document text
    • https://moveo-sport.pl/userfiles/file/puwozoli.pdfIn PDF document text
    • http://parvazyab.net/basefile/api203/files/lisedaxiwi.pdfIn PDF document text
    • https://majubesar.info/contents/files/guxigug.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/hs0i8jl1ta3msj425kdh4amo8e/91419261302.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/53369035661.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///99428095672.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_off0000c78f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC78F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dfa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA1 18232 bytes
SHA-256: 0f6ff93775f64593d618ad86e6014672aa2b6d6d4e4dcc364e552494908596c9
font_02_sfnt_off00010e18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E18 10292 bytes
SHA-256: fd8ec091266f06a54931af0fdb44b919dd3dddb9f0b7566bd7c9490af69f0a05