Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cd3ff93cdaef32…

MALICIOUS

PDF

81.1 KB Created: 2021-09-11 15:03:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-22
MD5: 7ce20fe0a17f3028c7d6f87f17c77cb2 SHA-1: 52aac0fea1864be658dc41a6d840be29402d6d59 SHA-256: 21cd3ff93cdaef321d8de4cd537abc09c0d6e7541d79b3aa30d4919f39ed2060
164 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 and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://proallprint.com/userfiles/files/kovutirokabe.pdf In PDF document text
    • https://kocgrafikavukatwebsitesi.demowebsiteleri.com/upload/files/wamamekem.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/12413532166.pdfIn PDF document text
    • http://stagticket.com/fck_upload/file/zepob.pdfIn PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/20802972072.pdfIn PDF document text
    • http://villacappuccina.com/userfiles/files/rimufu.pdfIn PDF document text
    • http://avvocatoandreabruschi.it/userfiles/files/46722401183.pdfIn PDF document text
    • http://zhhyhb.com/uploadfiles/files/nasubivosewepidejo.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/kogejiremixumozo.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/pulefexomomugibivo.pdfIn PDF document text
    • http://khachsandomino.com/hinhanh_fckeditor/file/64396123902.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c975e6b3bf---saripajogedewaladotebil.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/pazoxiluvol.pdfIn PDF document text
    • http://btfa.tw/upload/files/58989706573.pdfIn PDF document text
    • https://ipssecurityconsultants.com/ckfinder/userfiles/files/jitazuparofepu.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613904dd2aa5d---povep.pdfIn PDF document text
    • https://izometal.net/mm/file/dixibaxirisujibeliwurem.pdfIn PDF document text
    • http://ekmeta.lt/failai/file/memorupogavar.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/47596305382.pdfIn PDF document text
    • http://kanomax-nsk.ru/images/kibekexezuwewunuleva.pdfIn PDF document text
    • http://clinicaveterinariacene.com/userfiles/files/42859384707.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea800e5840---naguwudedabewapuwe.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/pisanewap.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613329e69f593---ronesizotolurovisa.pdfIn PDF document text
    • http://retailcop.ca/files/lexorena.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=watch+get+out+2017+online+freePDF 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_off0000d7ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7AD 17844 bytes
SHA-256: a2c420458324f46377f91c8731d6b725c4073f06c16e17bd23c09e0767d48645
font_01_sfnt_off000105ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105CE 10884 bytes
SHA-256: 7925562e54e5602bf1e00cd9be397f44d9742a063ce70a6b03cc42e4d16e8899
font_02_sfnt_off00011f14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1