Malicious PDF — malware analysis report

Static analysis result for SHA-256 a156bc9d08680338…

MALICIOUS

PDF

82.7 KB Created: 2021-06-11 13:43:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: d1d76abfaf02e6b53ec18cbdeb9dcc4f SHA-1: 881a789f9f3dd7bde332b214b7b16a988d0a2760 SHA-256: a156bc9d086803385058b0b808a41a4d38747771b44cd1d48ccc3ac8ba697a08
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://philabc.ru/uplcv?utm_term=new+england+journal+of+medicine+author+guidelines PDF link annotation
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16096f8861d78e---65377693048.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/39413752647.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609f97e6067ba---wikes.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/17725782413.pdfIn PDF document text
    • http://srihemkuntschoolint.com/slbdavbatala/userfiles/file/boxodupadozevig.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/ootucibpvfenp6u5981imksd35/36088197246.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/dccgoi793me72aintnamk7d7ma/11533096931.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16080f6ca9be6c---sopodo.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/17945461267.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b28a8ca77f---29486094699.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/2d09e61e8c356546fbdbbf0070ff0ed8/28582389807.pdfIn PDF document text
    • https://i-chat.tw/js/ckfinder/userfiles/files/66604092989.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911357ea478---finawaxemodedimerem.pdfIn PDF document text
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/gr0ld4ibo17gtbill3r361dnmj/gokedenesuradenanisugen.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607369f3d63fe---vojibewujojibozi.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1cd126cf3---2113710533.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086754c9548a---jejigig.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010329.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10329 5572 bytes
SHA-256: 442083cf8a0615de2ece12caa1429e2676e55cb7e9e86190ade3ac01f1b69937
font_01_sfnt_off00011611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11611 11608 bytes
SHA-256: f264fd391208b9192f9fe3c5d90fe3856bffccdad0e6962084b3133b813606f4