Malicious PDF — malware analysis report

Static analysis result for SHA-256 0841c3fb4fc73522…

MALICIOUS

PDF

72.0 KB Created: 2021-09-19 09:04:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3fd9f48527694959e16bb4bad28f99b0 SHA-1: 137aac61896f74417531fb84df3ce31199cf6826 SHA-256: 0841c3fb4fc73522261f982a0dfa0ac8fef56530c85bb4f39eaa3e4a3bbce178
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to link farms hosted on disposable domains, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings point towards a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9902

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://luckysurface.itweald.com/uploads/files/6137651065b60.pdf In PDF document text
    • http://expertsystemgroup.com/file_media/file_image/file/rutomevawo.pdfIn PDF document text
    • http://yarpb.ru/pic/userfile/92923675076.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/10972143161.pdfIn PDF document text
    • https://pushtypathshala.com/demo/aims/files/images/files/905263555.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/nizajomiga.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/58085432793.pdfIn PDF document text
    • https://sapsda.org/SapmaUserfiles/file/51358171482.pdfIn PDF document text
    • http://businessplan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/5374642658.pdfIn PDF document text
    • http://ekonopuntos.com/campannas/file/54668657690.pdfIn PDF document text
    • http://hadt.vn/upload/files/mikasimixebuzafifot.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/nonupepaviligugaguzizu.pdfIn PDF document text
    • http://sergeybazarov.ru/file/67358018710.pdfIn PDF document text
    • http://mega-stainlesssteel.com/uploads/image/files/29179488586.pdfIn PDF document text
    • http://pop-around.com/file_media/file_image/file/78262646636.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/45075156006.pdfIn PDF document text
    • http://mtt-association.fr/upload/file/tijirobirefolakefibilen.pdfIn PDF document text
    • http://houtackers.nl/userfiles/file/53091341263.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/2c23e89c9d2adec300f36b0876aab373/kobonupexegika.pdfIn PDF document text
    • http://www.portaldasfreguesias.com/portugal/vianadocastelo/vianadocastelo/geraz_do_lima_sta_maria/ckeditor/ckfinder/file/dijuvanilixifedidilanugob.pdfIn PDF document text
    • http://police8coop.com/UserFiles/file/98939248331.pdfIn PDF document text
    • http://silverk.ru/img/lib/file/xofunoxowexetiwulaxikem.pdfIn PDF document text
    • http://ltmetal.com/userfiles/files/saperategelu.pdfIn PDF document text
    • http://skipjackpoke.com/ckfinder/userfiles/files/dapifijizovojirikeb.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/tidajamomejunotupisegizos.pdfIn PDF document text
    • http://ambiance-cinema.fr/wp-content/plugins/super-forms/uploads/php/files/12d11f310575d4361f02be439a9ec5bb/20901323357.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=back+batan+appPDF 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_off0000b999.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB999 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1AF 9996 bytes
SHA-256: c8d49c552d82fe7e5049a2e6e65be0bb35d5d926780b4b36565a1a63ed470864
font_02_sfnt_off0000e7cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CB 16604 bytes
SHA-256: b78c3ab2c3cd01c0a9c341bf982c0adb0454175c06db6b1d9fffa40e23390e60