Malicious PDF — malware analysis report

Static analysis result for SHA-256 b44a23ac28fce4d0…

MALICIOUS

PDF

84.5 KB Created: 2021-09-19 07:26:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d0bfc1830b70f70b630b5539cba3dadc SHA-1: 5c109d368b73f9ee192549e6468af7f8b1660c3f SHA-256: b44a23ac28fce4d056248fd64ed3f3ef6dcb146230af16d5b437d79adc03c598
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external URIs and links to websites, many of which are hosted on compromised CMS upload directories or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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=solarmovie+app+for+android PDF link annotation
    • http://bio-scan.com/userfiles/file/duzirikiwoxidapokutav.pdfIn PDF document text
    • https://aayams.com/userfiles/file/48498199795.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/turelomufokisisikal.pdfIn PDF document text
    • http://dzirerealtors.com/uploads/buwutivo.pdfIn PDF document text
    • http://goldenagegroup.vip/userfiles/file/jivizewexafezabixolixeto.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/42754530147.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16141d0397da85---5334942201.pdfIn PDF document text
    • http://salespate.com/userfiles/file/fanop.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16146657e3b5ce---9418150961.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161371a1ed6426---panezunilov.pdfIn PDF document text
    • http://nigerseedindia.com/uploads/79667343123.pdfIn PDF document text
    • http://train-in-japan.com/images/blog/file/57873139354.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/sufajux.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.com/upload/files/zezumuwavipofar.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/lezowobifadizapupudej.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9962c6ead---56269029563.pdfIn PDF document text
    • http://articolo17.it/siti/usr/foto/files/vulupowefazuno.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140f039cdf27---46909457898.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/39706493237.pdfIn PDF document text
    • http://bukvoznaika.ru/ckfinder/userfiles/files/tidofe.pdfIn PDF document text
    • http://lammensfilip.be/uploads/files/gexapizijen.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/wekakapel.pdfIn PDF document text
    • http://gdgom.com/upload/file/2109091209375410039n3pk03cla9n.pdfIn PDF document text
    • http://jhdljz.com/userfiles/file/1631344297.pdfIn 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE603 18056 bytes
SHA-256: 010ab80c89b9d2f81fb225132c79c52ac118ba9b4ffcc9fa460822b1dbca5173
font_01_sfnt_off000114e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012cf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CF9 10532 bytes
SHA-256: d187b9dc16dc3fea53ede0b8158b819da50e1429746ceb482293586e24d43033