Malicious PDF — malware analysis report

Static analysis result for SHA-256 d91f3a3e0ea643d0…

MALICIOUS

PDF

78.4 KB Created: 2021-09-14 07:28:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: adadc6b3f89d548672cf17d946a42e50 SHA-1: 509d1df800914dab2f63888cd23887f1b0dad302 SHA-256: d91f3a3e0ea643d01eb76e14e5796abea2a1271481ebf92860d32c328d74702f
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs pointing to disposable domains, indicating a link farm designed to obscure the ultimate destination, likely for phishing or malware distribution. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, noting the use of disposable hosting and UTM parameters to track clicks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://rc-modeller.se/images/file///kezoduxezomogude.pdf In PDF document text
    • http://vrieshorst.nl/images/uploads/file/bituwuzikokusexuxiluxu.pdfIn PDF document text
    • http://koyomisushi.com/uploads/files/96688535116.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/xejipinedusosijabi.pdfIn PDF document text
    • http://prabashproperties.com/ckfinder/userfiles/files/kobesuzetutaj.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/5290049626.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/ladimu.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/38405509447.pdfIn PDF document text
    • http://art-ball.net/files/file/75806438004.pdfIn PDF document text
    • http://print-printonline.com/ckfinder/userfiles/files/5242920552.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/16136d5a5c4f13---vosibovamobomatowugobopif.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7d2e61cbe---73038763165.pdfIn PDF document text
    • http://sportingclubalbinia.eu/userfiles/files/bezebi.pdfIn PDF document text
    • http://wx-bm.cn/upload/ckimg/files/202109132254221694.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/kibilozakibaxixibidebo.pdfIn PDF document text
    • https://naucharts.com/ckfinder/userfiles/files/wusomubuxuzilavozosen.pdfIn PDF document text
    • http://lpxs168.com/filespath/files/20210903155657.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/fetadoxum.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/27212130142.pdfIn PDF document text
    • http://ewtch.com/upload/files/57170660190.pdfIn PDF document text
    • http://xn----7sbjvweekof5d.xn--p1ai/files/files/62942861026.pdfIn PDF document text
    • https://cargotavio.ru/files/file/5493795223.pdfIn PDF document text
    • https://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/zosodemaj.pdfIn PDF document text
    • https://cgeminfos.ma/upload/file/tazipixex.pdfIn PDF document text
    • https://wisestudentz.com/userfiles/file/biwep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=samsung+gt+s6500+android+updatePDF 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_off0000cb14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE326 17980 bytes
SHA-256: f14dfa80728ca12d5c3cc0305efda4eb8a684bef34c191be405b1dfeae9d316f
font_02_sfnt_off000111c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111C0 11288 bytes
SHA-256: 408ea1b34dc55517bb1cf1d7a51c12bc8a32494a611bc98285051cbf21f12a91