Malicious PDF — malware analysis report

Static analysis result for SHA-256 2028091d8fb7d3d9…

MALICIOUS

PDF

93.4 KB Created: 2021-08-07 09:15:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 81e2aa4ba3ed1eeebd603f33f00a70e3 SHA-1: 726873ff9c5c0ca92bdc5afd1e9bd9690c3cb5c7 SHA-256: 2028091d8fb7d3d952da35b71dc503f20ea8e7d5e3d480ddeec982a68e12d428
96 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 websites that appear to be compromised or use disposable hosting, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted, and the document body was unreadable binary data, suggesting the primary function is to redirect users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 5

  • 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://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/8db4pj6iuppp7v1oui77kbar41/finukaz.pdf In PDF document text
    • http://akcjonariusz.com/UserFiles/file/dugugejenabox.pdfIn PDF document text
    • http://dichvuketoansg.com/luutru/files/xusalowi.pdfIn PDF document text
    • https://ville-saintleonard.fr/pdf/99397287613.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/29918235416.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1a8503d86---39824920850.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/29452262361.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/tozamanoxituga.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/mufezonureg.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/jugonudobadad.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb55826f13---zunerajutidaniwemaf.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/jotegufimoxivujizemexume.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/13241097084.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/d99cdbbe1cf90117be9a77ae8af6c6a7/balusedalof.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/84311924267.pdfIn PDF document text
    • https://farmstead.tw/farmstead/upload/files/tejorerevumupajiwuro.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/36536939125.pdfIn PDF document text
    • http://dakmet.pl/upload/wubenelav.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/3423e70531530ba6b5b91b1f4523e025/35831111090.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/cb531600e0a95520ce169bf025b0697e/pujabul.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/164bd0dfeeb41ca5893e489d7fc1107f/502582193.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608265e306807---bopegizodatanutixezas.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/41399416182.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160729b6027c1c---62245981189.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=adverbs+of+frequency+british+council+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_off00010592.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10592 17888 bytes
SHA-256: 2780af9ed34bcd5b103714e854edfbbee822d2838f9ba48f91edf8df44362242
font_01_sfnt_off00013403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13403 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014c1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C1A 11100 bytes
SHA-256: f74268bc5f4bd76f5f232d960062ee1e0eb4e0d2c6c53e4b3d926d9d8c81da35