Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fa5f53de26626cc…

MALICIOUS

PDF

71.6 KB Created: 2021-09-16 03:22:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ff93f4fc68b16a3dd0cc408bf537556b SHA-1: fbddf287160520bfc5ac97b863b8a560a37afe42 SHA-256: 5fa5f53de26626ccf03cfce952d994f602b7dca020fad40235ba0855f925582f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised websites or link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The presence of external URI links suggests an attempt to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://smidgel.ru/uplcv?utm_term=how+to+unlock+an+android+pattern PDF link annotation
    • http://precisao.org/files/files/relixinedagewiz.pdfIn PDF document text
    • http://cachnhietcacham.vn/Images_upload/files/nilebesawubuvix.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/wowefufugelewefujikeruber.pdfIn PDF document text
    • http://globalbizkorea.com/userData/board/file/24079782061.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/fejolewiverapaja.pdfIn PDF document text
    • http://paraleumarian.ro/app/webroot/files/userfiles/files/burojabawojazadufafifevir.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/tosadigamevavadixudesag.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/k94vnt7mjg9b710tuvhr9l77md/finonazudezibuvapowogo.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16139a822ed580---92193394307.pdfIn PDF document text
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/tivugijefegego.pdfIn PDF document text
    • http://redemaisfarma.com/userfiles/file/kobixodevemogin.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/9116951273.pdfIn PDF document text
    • http://www.instalacionescueto.com/nueva/ckfinder/userfiles/files/zuzugewaboju.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/80914165018.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16142290532cf5---36573033963.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/78503943815.pdfIn PDF document text
    • http://decoworld.in/dayafter/uploadimages/newsimages/file/kafaponesosuzufaku.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/5676822256.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613328dc9102d---dokanesufiriwol.pdfIn PDF document text
    • https://zhansq.cn/upload/file/buzuxusenafi.pdfIn PDF document text
    • http://tomboy2.com/images/library/File/11992540936.pdfIn PDF document text
    • https://corpus.bg/files/fck/file/masatekero.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_off0000b536.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB536 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD48 16672 bytes
SHA-256: fdd21fda702d28fdbe8383aec4e48736885205ed599824461a9154f1335cc849
font_02_sfnt_off0000f832.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF832 10608 bytes
SHA-256: f9b0264dadd23f9ff97f576aada70fd75af2716376577a293bdd3f4e52ad38ae