Malicious PDF — malware analysis report

Static analysis result for SHA-256 4240c15f0bff3e4f…

MALICIOUS

PDF

71.1 KB Created: 2021-09-25 23:10:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a1ea50607f00792cb94e0dc68aaad501 SHA-1: 1c76b1717449dd981d151c3274625048c9ab848e SHA-256: 4240c15f0bff3e4fe2d91002b07d2462f37c4f938a57b4e789e1d06e2da888e7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The presence of 'redeem+code+mod+apk' in one URL suggests a potential lure for users seeking software or game modifications. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 https://chcial.ru/uplcv?utm_term=redeem+code+mod+apk
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da6c90737f---25840107204.pdf
    • https://netiko.fr/img/Data/file/98792889465.pdf
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/4275366321.pdf
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fad225d2bb---sizakof.pdf
    • http://pantipplaza.com/userfiles/file/11873471054.pdf
    • http://westernmaki.com/uploads/files/gelilumusa.pdf
    • http://sevinctekstil.com/resimler/files/40718414408.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/742ca80fbe2ded37eddd6863d88a6a36/rajep.pdf
    • https://biorenta.lt/ckfinder/userfiles/files/81528346477.pdf
    • https://afayl.com/userfiles/file/gexuvoraruk.pdf
    • http://fatfailogistics.com/fckeditor/files/file/muten.pdf
    • http://caffepontoni.com/uploads/file/xakamunajemofojerigutas.pdf
    • http://hoaisonland.vn/upload/files/gudatinevekinaket.pdf
    • http://medeeatour.ro/mm/file/21716957322.pdf
    • http://edv-denk.com/userfiles/file/68488138627.pdf
    • http://bbfrontedelmare.com/userfiles/files/tatuzaminu.pdf
    • https://chambredhotes-savoie.com/ckfinder/userfiles/files/fuxesepapa.pdf
    • http://chiengthai.com/file_media/file_image/file/tumamo.pdf
    • http://luijkzonwering.nl/image/file/90958145540.pdf
    • http://dhleisure.com/ckupload/files/26156657918.pdf
    • http://xinyuemu.net/assets/202109/files/20210907060010286211.pdf
    • http://lumieye.com/userData/ebizro_board/file/vewajukerezadowigapu.pdf
    • http://brenno-tojestto.pl/userfiles/file/78219437071.pdf
    • https://chowdhurytourism.com/ckfinder/userfiles/files/95437720067.pdf
    • http://ozdesignhouse.com/app/webroot/uploads/files/kenenujadal.pdf
    • http://abwhopewell.com/uploads/files/56862041289.pdf
    • 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_off0000b4f4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4F4 16792 bytes
font_01_sfnt_off0000cd0b.bin
a1a2b211bb1aa4879568f948cdedbaa5032263c8001bbc9dd29183f1faaf4d0d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD0B 10204 bytes
font_02_sfnt_off0000e3e7.bin
2a41d2d4dbf7012f7b2bcf070b283103163856a5437ffac69fa962d9ba1e178b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E7 16812 bytes