Malicious PDF — malware analysis report

Static analysis result for SHA-256 a99fc40605c108e2…

MALICIOUS

PDF

71.8 KB Created: 2021-10-01 17:17:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 31f1b2dbe2c68e5bae109c3c9efea7c1 SHA-1: d4dc356d28af07b41549aee5f262d62e5212dd2e SHA-256: a99fc40605c108e23506ebb67b34f5f50b94c863b38783590313259b0fa2678c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on compromised or disposable domains, forming a link farm. This suggests the document is designed to lure users to external sites, potentially for phishing or to download further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://pinturasoltra.com/images/slider/files/zofadozudetebuvidibe.pdf
    • https://hanoihome.net/img_duhoc/files/nugobopoxafi.pdf
    • https://tcremich.lu/files/files/33092389323.pdf
    • http://sbairs.com/datas/files/gaponoxugorixezi.pdf
    • http://yenidenyuzlendirme.com/ckfinder/userfiles/files/6316870419.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/161459ee630e07---zudexaj.pdf
    • http://gbfrjournal.org/pds/userfiles/files/gufiwisuxinixepujes.pdf
    • http://bitree.net/ckfinder/userfiles/files/xumalaresur.pdf
    • http://traslochimontalto.it/userfiles/files/bukenajajinofavolomito.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613627cb8dc0c---lesopuleronoluwa.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131f550926f1---kafanufifepowaxaf.pdf
    • http://www.jacenter.org/js/ckfinder/userfiles/files/86344210469.pdf
    • https://g-mtcc.com/motakamel/Ups/files/22617243290.pdf
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/59078108276.pdf
    • http://binhchuachay.info/Images_upload/files/49597311344.pdf
    • http://estatepie.com/files/userfiles/file/falujinopipomid.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613be8fe10eb6---86132729259.pdf
    • http://paroissedementon.fr/upload/files/bejodenosozedavirukutanaf.pdf
    • http://net-marketing.hu/images/files/mutujalarinaxegadofenu.pdf
    • https://s-oil.hoakhanh.vn/uploads/image/files/fumudufivugasonatu.pdf
    • http://eko-uklid.com/files/file/bamigifisifojonafolojazu.pdf
    • http://e-park.es/img/uploads/files/72257343219.pdf
    • http://uforoi.com/app/webroot/uploads/files/10965854045.pdf
    • http://kppzp.pl/userfiles/file/25859956441.pdf
    • http://ufnk.fr/app/webroot/files/file/xikavatosakud.pdf
    • https://xtrafitcoaching.com/www/images/files/89231982459.pdf
    • http://utpcomp.ru/uploads/files/86382288556.pdf
    • http://wumag.pl/userfiles/file/gidezuvobidelibenuw.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=free+download+youtube+music+premium+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b5fe.bin
36b426fab3f3bd8f422eb115e4ba9b1e42d97e429d21ae74936cdfb93ada7aee
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5FE 11184 bytes
font_01_sfnt_off0000cffc.bin
dad2475c83428260c6a337e8b71af0893706769edd69d044305ccd004d696866
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFFC 16088 bytes
font_02_sfnt_off0000f926.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF926 16792 bytes