Malicious PDF — malware analysis report

Static analysis result for SHA-256 23f99ee3f997fa6e…

MALICIOUS

PDF

84.3 KB Created: 2021-09-07 18:56:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 163cf6c2d209c37a00e1a92383ae5b77 SHA-1: bce01db4d144eb54f871e084c4e8716df2763b52 SHA-256: 23f99ee3f997fa6e237b44aeb1f9c835d6924b15150574f6751595575bdb5b93
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed for SEO manipulation or phishing. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://tinhdauvietnam.vn/upload/files/48992583659.pdf In PDF document text
    • http://dok-vo.ru/userfiles/file/tuxodomugonuru.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/122a8fdf164aa08851d352cc43b4ab10/rawoputamigizej.pdfIn PDF document text
    • http://dkyangmei.com/uploadfile/file/2021080411372873499.pdfIn PDF document text
    • http://beamstraffic.ae/amb/userfiles/file/fokunojabiputakogu.pdfIn PDF document text
    • http://dep14kirov.ru/userfiles/file/48986794961.pdfIn PDF document text
    • http://miele-service-center.ru/uploads/files/tozawokomafajupijido.pdfIn PDF document text
    • http://101balkon.ru/upload/files/butoxokukom.pdfIn PDF document text
    • https://wronba.pl/uploads/wysiwyg/file/saromoxalemirop.pdfIn PDF document text
    • https://gkia.org/kingkong/userfiles/files/kekerodimobiv.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/rebifopejebemof.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/vaxed.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611e9eb16dd08---22848170120.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080ac0ca4b45---jojokuf.pdfIn PDF document text
    • http://donghocitizenchinhhang.com/uploads/userfiles/file/54259629471.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1610c6ed086ad2---30275511625.pdfIn PDF document text
    • http://kbinteriery.cz/userfiles/file/59398871255.pdfIn PDF document text
    • http://wisdomtours.net/upload/file/wowapunuxejamavunobax.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/fawakujosebifaramido.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/9914932416094646ebbfed.pdfIn PDF document text
    • https://ecoledesgourmets.com/userfiles/file/79282272790.pdfIn PDF document text
    • http://xn----dtbsgbucafmmaf.xn--p1ai/servimages/editor/files/gavajisogufa.pdfIn PDF document text
    • http://mallenmediations.com/mallenmediations/images/userfiles/file/84964723922.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=beatles+song+chords+pdfPDF 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_off0000e287.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE287 18500 bytes
SHA-256: c1470933c15f8b8941262cac345a58106776e606544b2a99b8435609b4e58f4f
font_01_sfnt_off0001125f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1125F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012a76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A76 10860 bytes
SHA-256: 8d65145fb00c015ccc6010547cfcab7b728027158336739b49d98735908a1c32