Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8a056d5c1b7ba14…

MALICIOUS

PDF

86.7 KB Created: 2021-09-15 18:51:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: cb5a1cf0f31f3646fcab76dbc436cdac SHA-1: 8d9d30f4037733a3740409d1aa851189a9e2e0d8 SHA-256: a8a056d5c1b7ba14a47df6d962a913f1ddc17f54958ba1e0931d8aad111d563f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/ed3c4eaa95930e935ce672df0baec0f1/vekiludasum.pdf In PDF document text
    • https://auditorescr.com/ckfinder/userfiles/files/vevuwividakipoduw.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/35754946448.pdfIn PDF document text
    • http://jawarakreasi.com/file/benefakasa.pdfIn PDF document text
    • http://npas.ru/pic/file/sufogakufedugeriret.pdfIn PDF document text
    • https://noursportevents.com/wheelmarine/userfiles/file/rojusiligirob.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5a53c1eef89521af8d195740b6f72472/26232996523.pdfIn PDF document text
    • https://tavfelugyelet.megujuloenergiapark.hu/admin/ckfinder/userfiles/files/dovafeselatopogifokiwisiz.pdfIn PDF document text
    • https://salvatoredivilio.it/userfiles/file/42845011427.pdfIn PDF document text
    • http://koslita.eu/ckfinder/userfiles/files/14595417420.pdfIn PDF document text
    • http://khunghinhdepphuctin.com/media/ftp/file/kewate.pdfIn PDF document text
    • https://mchs.kz/userfiles/File/sibizawokakorokuvigawim.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210907205307.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c5c639aa5---dosolu.pdfIn PDF document text
    • http://www.tecs4.com/intranet/ckfinder/userfiles/files/50768601811.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/danogak.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/76863049880.pdfIn PDF document text
    • https://ingatlansos.hu/images/userfiles/file/50826440252.pdfIn PDF document text
    • http://kurier48.pl/files/userfiles/file/35819510656.pdfIn PDF document text
    • https://eghamatkade.com/basefile/eghamatkadecom/files/59624286220.pdfIn PDF document text
    • http://www.nena-artspace.com/ckfinder/userfiles/files/wutudepadenap.pdfIn PDF document text
    • https://grootformaatspandoeken.nl/userfiles/file/34561160362.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/puxigekumeduja.pdfIn PDF document text
    • http://youngdongtec.com/userfiles/file/16077068262.pdfIn PDF document text
    • https://krassimirtaskov.com/userfiles/files/88044752980.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=introduction+to+modern+climate+change+2nd+edition+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_off0000ec8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8A 11072 bytes
SHA-256: 009c065cd71b771c8bd4d9142f2df8d00aa997b3841c27eeb72f10b20fd5c6e6
font_01_sfnt_off000105f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F0 18156 bytes
SHA-256: 6fcc66c229b11239a19cd0a503404e26d09dbb983c04a8be6a75b18305d3f8b2
font_02_sfnt_off000134a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1