Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3fb139c08d5e8ab…

MALICIOUS

PDF

89.7 KB Created: 2021-09-11 13:52:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 87ef35a2788785cead279b87951fb1c4 SHA-1: 7f9d890c5e30610abb7159bd714aa18d8f80459f SHA-256: a3fb139c08d5e8abc9daa9626f6b4e7f87483aaa47dbd552e184aaeb60b36f97
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML and ClamAV as malicious. It contains numerous embedded URLs pointing to a link farm, with many of these URLs leading to other PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for a large number of links, suggesting a malicious intent to distribute or host phishing content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://versobrokers.eu/userfiles/files/38350660709.pdf In PDF document text
    • http://studiomalpocher.it/userfiles/files/34222145114.pdfIn PDF document text
    • http://linhkienhunganh.vn/luutru/files/dipuxirijewoxivadexute.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/zedanugeletubobekugapowav.pdfIn PDF document text
    • https://vasutaszeneiskola.hu/ckfinder/userfiles/files/dupolojuzinitisovokip.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613390ac53e77---repiluzoje.pdfIn PDF document text
    • https://wasael.com/userfiles/file/bijurejelo.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/80126751401.pdfIn PDF document text
    • http://igabana.com/upfolder/e/files/20210911142730.pdfIn PDF document text
    • https://tanhaithanhvalves.com/quangcao/admin/file/ziwegabonazoxote.pdfIn PDF document text
    • http://equipociclistaugeraga.com/ciclistas/userfiles/file/77560511809.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b55c459124---gumiwoxujagoforiwuna.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/70423022599.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/64007257804.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/49082948192.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/vugiguf.pdfIn PDF document text
    • https://lifeteacher.tw/uploads/files/202109071536317957.pdfIn PDF document text
    • http://boxshop.mn/userfiles/files/nefavagegadasuxujezez.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/58010059267.pdfIn PDF document text
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/dapesedobetizisafomezagak.pdfIn PDF document text
    • http://koovappadyscb.com/ckfinder/userfiles/files/xumegevutuxovenokigajogo.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kaluxib.pdfIn PDF document text
    • http://bastola.org/userfiles/file/48062510529.pdfIn PDF document text
    • http://fxlcd.com/upload/file/kujobije.pdfIn PDF document text
    • http://brixtontaxi.com/survey/userfiles/files/22972998944.pdfIn PDF document text
    • http://tostonet.cl/ckfinder/userfiles/files/notiritilatevanuvi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=among+us+free+pc+2021PDF 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_off0000f766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF766 18636 bytes
SHA-256: 1e115760066348a96c4ea2a808053834291f685bdd7058f7833921b931daf723
font_01_sfnt_off000127e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14000 10800 bytes
SHA-256: 6c26f946d0c6def31949dc81fbf1f53f977f004f83e9ce3b2bd80da60655ee14