Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c917b546d42795…

MALICIOUS

PDF

75.6 KB Created: 2021-06-21 09:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 7b3febd4afad17b5bfea206cc5a16c22 SHA-1: 6ef51fe9c973b8b0dd1c777aee9bb52a065aa57f SHA-256: 91c917b546d42795d29004e8057ea90679b95ce6478c2f45e2d935bfca11a67e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious. It contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised or disposable, suggesting an attempt to distribute malicious content or conduct phishing. The presence of embedded URLs and the nature of the link farm heuristics strongly indicate a spearphishing attachment vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://4x4autok.hu/userfiles/files/24329690940.pdf In PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2fbb1b4685---boxireguvavavuzekif.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/bumenir.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cae5e1814e---refolebekejabositibujojod.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/sugudi.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/cdic9bru18hjuadp2grsrfjl5c/golazakakom.pdfIn PDF document text
    • http://yogo110.com/userfiles/file/nuvimoderev.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa961c64956---zudozubolubixege.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/72723c03c5be2aa34cf9cdd0eaa258fc/gopuludapopiwepisaluf.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/e44de6539266a84913baf046fb9a941a/gexakuto.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/laturufawib.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/4b14f7d9765547774330797543645618/85087637296.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/1c90c6aa03847995c497d5a3ef02fb10/29046356872.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9ff651a0a---zuxavaw.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/c594319dfb872e5f5493e58b0f88898b/90049714732.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/55f5edf6768e38084cf4a94a86108380/54807360219.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b87b8fe4428---puvufaketivurof.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/441ddc99c653a931f2edb567770a1a32/tisip.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=new+th13+legend+basePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB90 5408 bytes
SHA-256: 7f47ecc41bf3f3f6afae91f3338bf368926d7cac8e8ad8eaf546cfe33c65091c
font_01_sfnt_off0000fe13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE13 10360 bytes
SHA-256: 31f6dc8a0ef213a42cbe603a7cd91cb1c122b5e50ee294fec11add6b7d6cc49c