Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba7dd1c5942ee6da…

MALICIOUS

PDF

80.9 KB Created: 2021-09-03 02:03:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e599e18758b67edf0bf6e1054bbb42e7 SHA-1: e85e4fa6616b02818ac6910800fbd2969ae2e477 SHA-256: ba7dd1c5942ee6da1a269b27a7c1e06c2258a5855ebfb1fbc475779bec84baaa
156 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 compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the heuristic findings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://pistant.ru/uplcv?utm_term=math+worksheets+solving+linear+equations PDF link annotation
    • http://nature-revive.org/files/file/keburovutedu.pdfIn PDF document text
    • https://vicotelecom.vn/static/source/images/file/57188784286.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/jujizivenu.pdfIn PDF document text
    • http://spostojow.pl/userfiles/file/83831574384.pdfIn PDF document text
    • http://berbun.com/user_img/file/81266097744.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/fcu5b9dsqfnhnahr1k67da1dhd/jerepupexof.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/pulepok.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/79969128168.pdfIn PDF document text
    • https://barcelonamedicalcenter.com/files/galeria/files/bonamijulefegimaretufog.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088d3ec17283---66741114802.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/ahfq9er40ilvr1n746o8mqhm23/95353572796.pdfIn PDF document text
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/subumataxakuju.pdfIn PDF document text
    • https://peilimineko.com/userfiles/file/73529102895.pdfIn PDF document text
    • http://studiogalata.it/userfiles/files/pufosoravolugiful.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/1609e0ec2cb2ff---wulagejagujaxukodupabuju.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/18facd5cff1589da40e90a03c696a6e3/gutoroligewovaduvo.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/a4c0885f58dae06ee4cc7d4e50c4fcdb/nokogur.pdfIn PDF document text
    • http://harasim.cz/uploaded/files/26792999933.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/161067747af334---jufidisovupesatipepoge.pdfIn PDF document text
    • http://janyska.home.pl/_mjanyska2013/fotki/file/modememabo.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_off0000d71a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD71A 10868 bytes
SHA-256: 076ff132dc20de42c7dcd9ed003a382bab79cbecbae48671bcbba848be69e4d7
font_01_sfnt_off0000eff2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF2 17900 bytes
SHA-256: 0e513b9a2f333b382e542c8799128af08969dcb4ff36cb5241d08c607e15e55d
font_02_sfnt_off00011dd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1