Malicious PDF — malware analysis report

Static analysis result for SHA-256 8533d70f6f7bbbb6…

MALICIOUS

PDF

88.6 KB Created: 2021-06-20 14:15:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 72e838c5c4fa2436a0aafd18e8b9ccb8 SHA-1: 433fe56e4650eecf7172ec146a1fbb625cf57ba9 SHA-256: 8533d70f6f7bbbb60fd2d46d72716bd158c6534cb13f57e5a6e47a4449f92ae1
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to exploit users by presenting a seemingly legitimate document that leads to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 https://crysiq.ru/uplcv?utm_term=fundamentals+of+thermodynamics+10th+edition+pdf PDF link annotation
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d98024e0a6---konazom.pdfIn PDF document text
    • http://nakatka.com/files/file/64365369306.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088fbd27dfad---zozigo.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/ec15ddf3adf3bfbf1749569fcd7ff04e/wetawaxozimiwusivudu.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/xenonajasopovarebabu.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160865043c09b3---73202123481.pdfIn PDF document text
    • https://www.profiemg.cz/upload/ck/files/54997978528.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/11ofgukg20k279dgbat65st3u6/44515382030.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/a4df40199c5a185ea854324eed97aaf6/8398134523.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c3c10486e---likuzivexekuxibofofi.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/tiwomidugagagifigizezu.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/125da0f2cec109e1fe9d807c3143a358/70043448962.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/5254d4c377811869fb14fe6c9b641b65/60284240686.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160a4be2f701de---4601762360.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607247dab16b7---gojolatifikivoziwodoti.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off0001236b.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1236B 26796 bytes
SHA-256: a3ace528eabf2bdca29f0d0d615b99f408e4c660b8c12905862b4c0d502abd83
font_00_sfnt_off0000ebce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCE 5644 bytes
SHA-256: 9aedf0e92153cbb879bf40fd454156026d6fb9de6e46b4797af926f8abe20b9b
font_01_sfnt_off0000fee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE9 10668 bytes
SHA-256: f7e6de2c3c4284c686c40f22f2ce7fd0b579e0db40385c7d0ac8f9d118b39cef