Malicious PDF — malware analysis report

Static analysis result for SHA-256 c21aca69d23d7d0d…

MALICIOUS

PDF

81.7 KB Created: 2021-09-14 01:50:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 86f2be149022dc0826c190b597694275 SHA-1: 91049e14c1267dabb4d50e1533d410823081d1f1 SHA-256: c21aca69d23d7d0d25189c49952bf5d1888fc5733ba4b751b31b249f6307bb3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. Although no scripts were directly extracted, the structure and URL patterns are consistent with malicious PDFs designed to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://dichvu12h.net/userfiles/file/3094150075.pdf In PDF document text
    • http://arucax.am/user_images/file/dubakujolumixegawez.pdfIn PDF document text
    • http://akifkasaboglu.com/esatfisek/images_upload/files/pevesutulepokememugefo.pdfIn PDF document text
    • http://www.clc-engineering.com/siteuploads/editorimg/file/4856779047.pdfIn PDF document text
    • http://inciboya.com/resimler/site/files/33763399448.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/xigemojikanod.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/74300961784.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/voladok.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dbc1836edb---giduwikevi.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/fazupumewurabupetexu.pdfIn PDF document text
    • https://hantverkarenisandby.se/UserFiles/files/jisenodewamabuwolok.pdfIn PDF document text
    • http://020tzs.com/baige/images/userfiles/file/vasiwawojojodute.pdfIn PDF document text
    • http://www.hon-ro.hu/userfiles/files/98969294016.pdfIn PDF document text
    • http://herborgthailand.com/file_media/file_image/file/29681718503.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/bojiwizavijeb.pdfIn PDF document text
    • http://www.facyt.com.ar/ckfinder/userfiles/files/sajufopiviwapolewe.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbede87cc2---27000931606.pdfIn PDF document text
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/16452869067.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/0c5bdfe572ca1c6b646d3107f86cb613/mipegemabirigimu.pdfIn PDF document text
    • https://estatecambodia.com/htdocs/cljr/data/files/bafifa.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/10124861710.pdfIn PDF document text
    • http://islenapuntos.com/campannas/file/90164732059.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=samsung+galaxy+s6+release+date+australiaPDF 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_off0000d56d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD56D 19288 bytes
SHA-256: 7ad5f39045dcf8d59c8804534126a97da7bc04c01b4e83f69c5b4072d4a93f98
font_01_sfnt_off000107f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001200f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1200F 11032 bytes
SHA-256: 93957d48d00245b742714255310e8e32e17201452f592f5ee04655f04ce4ae65