Malicious PDF — malware analysis report

Static analysis result for SHA-256 786d21a38e480435…

MALICIOUS

PDF

74.9 KB Created: 2021-09-17 10:19:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c186b0a6c7ef18cbf8f30ce33299e8f0 SHA-1: 6e0998fea35a97d3e218ce699419ef5704e9b875 SHA-256: 786d21a38e480435b3e6b4e0b2771db99786f5d6859f66c92f3cad76fefcd9e2
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO poisoning. The presence of multiple external URIs and link farm heuristics points towards an attempt to manipulate search results or direct users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://vinhthuanvietnam.com/upload/files/pelufeberi.pdf In PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/pinujojetegitexonuto.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/47664278365.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/54875871585.pdfIn PDF document text
    • http://ativn.com/upload/file/sedibexukoxugalipex.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/32e06447d489c8ed3a9e03b20bbf62b8/6421237599.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132e74e07a9c---1015626697.pdfIn PDF document text
    • http://avs-market.ru/admin/ckfinder/userfiles/files/pepuruvugu.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/kepakovowokopofijatovav.pdfIn PDF document text
    • http://tieuhocsondong.hoaiduc.edu.vn/ckfinder/userfiles/files/sowinavizoputomajone.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef0d7ed889---35487587163.pdfIn PDF document text
    • http://chickendaylacrescenta.com/uploads/files/84934857746.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/sojot.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/xizujezaxemenog.pdfIn PDF document text
    • https://yantrasearch.com/ckfinder/userfiles/files/32380202466.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613012ff4a5f7---72909381595.pdfIn PDF document text
    • http://espwireless.net/uploads/file/bamojabedapuratudexi.pdfIn PDF document text
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/zewebofazuj.pdfIn PDF document text
    • https://medarbindia.org/ckfinder/userfiles/files/42224599263.pdfIn PDF document text
    • http://www.elmundodelapiscina.com/ckfinder/userfiles/files/saxetifagolul.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/45751709464.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/9359873831.pdfIn PDF document text
    • https://chsins.tw/uploads/files/202109040811521195.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=auslogics+boostspeed+for+androidPDF 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_off0000c18b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC18B 11016 bytes
SHA-256: 7dd91d61f6605b2dbb722d82290f61afbc4608a63e38990da9862ab2009ad3dd
font_01_sfnt_off0000dade.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADE 16644 bytes
SHA-256: 6370d944499f02938bcae41329f8ac7059463d33308d03821e34e0ff50fa1333
font_02_sfnt_off000105ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1