Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c5065dd376f0eba…

MALICIOUS

PDF

69.1 KB Created: 2021-09-28 11:09:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e9c3aab1f597d03d6c4af93649bdfecf SHA-1: 58535b78aac6b13d02aeb349b76511528dd64d22 SHA-256: 3c5065dd376f0ebaf5c92d25be2c06e752e6a9b733872442d2a265d659c6d3b5
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the presence of numerous external links strongly suggests a malicious intent to redirect the user.

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://filipdegreef.be/uploads/files/sugelomewurudawezogek.pdf In PDF document text
    • http://byty-pardubice.eu/UserFiles/File/13491026502.pdfIn PDF document text
    • http://flagrant-desir.com/userfiles/file/82504521603.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16315776006822.pdfIn PDF document text
    • https://processwork.archerhuang.com/ConImg/files/24009541145.pdfIn PDF document text
    • http://jongauger.com/userfiles/file/naduvotigetavavepudarojam.pdfIn PDF document text
    • http://checopharma.com/upload/files/vomet.pdfIn PDF document text
    • http://www.polni.si/Images/files/3326547579.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/dunilusuviz.pdfIn PDF document text
    • http://murielbellhomes.com/userfiles/files/gabugevepe.pdfIn PDF document text
    • https://osikovo.eu/webroot/img/content/files/17978911718.pdfIn PDF document text
    • https://nwdglobal.com/ckfinder/userfiles/files/59144927130.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/kususolunesob.pdfIn PDF document text
    • http://oodow.cn/upload/file/210913024711468699p5t62nn8by78.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b86eb0c7c5---89972567148.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/f3b5daba0c0be8f945b9bbd1e4a8e2d2/97843755272.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/abf3a36d907833dc94e4fed0a239ba32/49038813814.pdfIn PDF document text
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/7748380700.pdfIn PDF document text
    • http://globalone-mould.com/gbw/fckfiles/20210906235227.pdfIn PDF document text
    • https://www.poole.ed.jp/system/ckfinder/userfiles/files/bixibomuwapelirasaked.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/fexanijomutupomoboke.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/34349988073.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/bugujir.pdfIn PDF document text
    • https://satuldelut.ro/ckfinder/userfiles/files/nenubenada.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=ff+tactics+gbaPDF 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_off0000b2c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2C5 14888 bytes
SHA-256: 5641ab7fc7661ff13610c4e3fd3cd5b2f2b13725a5d5f60ca040554400f36c00
font_01_sfnt_off0000d80f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD80F 10124 bytes
SHA-256: 0f8f6ba97eb33f36e8494f1a4bdd295fa350502e45a763198c2529ce33538684
font_02_sfnt_off0000eed9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEED9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1