Malicious PDF — malware analysis report

Static analysis result for SHA-256 d395f91c6673af43…

MALICIOUS

PDF

78.3 KB Created: 2021-10-25 15:46:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 9fa8df391267e0c0c227343ddbdc011f SHA-1: 7484966e82964c467aa2119c6de909ed886d82ad SHA-256: d395f91c6673af4357d3da7a0039ecfd057d2f65a56acf205f589bf4e420bb72
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external URLs that point to other PDF files hosted on various domains, some of which are associated with compromised CMS uploads. This structure suggests an attempt to distribute further malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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 http://proficlim.ru/public/userfiles/file/53763704610.pdf In PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/bc29e2d053adc2fe95c1b1a330be93c4/49204345067.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/33798918766.pdfIn PDF document text
    • http://calisnt.com/uploads/files/19220698846.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/rebitebixuganer.pdfIn PDF document text
    • https://semot.com/Store/userfiles/file/50624402278.pdfIn PDF document text
    • http://neoneofitou.com/ckfinder/userfiles/files/lidixubajinanesajojuwagu.pdfIn PDF document text
    • http://studiofagiani.eu/userfiles/files/65273197381.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20211013012147.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/userfiles/file/72514867117.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16172cead604e1---58572678938.pdfIn PDF document text
    • https://cicadit.ro/UserFiles/file/xoponurazi.pdfIn PDF document text
    • https://wintechindia.in/ckfinder/userfiles/files/6676585014.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/38253564417.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1614ae0469669f---zonebasirujaziverufefi.pdfIn PDF document text
    • http://studiomistretta.com/userfiles/files/59017922212.pdfIn PDF document text
    • http://sladkiy-ostrov.ru/userfiles/files/75271798712.pdfIn PDF document text
    • https://pensiuneaselina.ro/userfiles/file/duzivakidiwerazero.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/7ab770d8f5a645542bcb4c9aa13d8e5a/78611568742.pdfIn PDF document text
    • https://abbma.in/admin/uploads/file/40308142130.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/dumisebavome.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/RhDyTiV0TgQ/uplcv?utm_term=word+maker+gamePDF 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_off0000cf93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF93 17708 bytes
SHA-256: a18e46dea74f418e178d22c356e667d11199d3cb7acfdccc2145b8b35f54c3c8
font_01_sfnt_off0000fd84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD84 10168 bytes
SHA-256: e8f100ef4d4fd8ae4a3104bfcf71618bc5261bb7972dc9b32ef20062cc2c92f3
font_02_sfnt_off00011417.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11417 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1