Malicious PDF — malware analysis report

Static analysis result for SHA-256 848e638c89644656…

MALICIOUS

PDF

88.5 KB Created: 2021-09-04 14:13:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 857aae8d89a320eeeb362e6256c31319 SHA-1: 34c10a0d56105d47dcf9be92fb8fdc3a256dd9de SHA-256: 848e638c89644656ba0fb03dd182857d25c21f87be2ff04fbe5f846abcab9035
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs that form a link farm, pointing to various PDF files hosted on multiple domains. Several of these domains appear to be compromised CMS upload directories or disposable hosting, suggesting an attempt to obscure the ultimate payload or engage in SEO manipulation. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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://valeneighbors.com/userimages/lanulelurolekikikol.pdf In PDF document text
    • http://hongdanhaudio.com/luutru/files/vogitexawoxuzubojo.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/tojavutiziwower.pdfIn PDF document text
    • http://kids-ex.com/98653953209.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/bezetubabijunajepowupat.pdfIn PDF document text
    • http://www.vnos.vn/app/webroot/uploads/files/96754515690.pdfIn PDF document text
    • http://coatsofarms.com.au/ckfinder/userfiles/files/katokumepigamagenanakuput.pdfIn PDF document text
    • http://modern-pro.ru/files/file/munowunagaroniw.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/userfiles/file/wipiwebarudupamovelup.pdfIn PDF document text
    • http://robedecreateur.com/img/files/8049902484.pdfIn PDF document text
    • http://aroma-es.site/yamituki-n/uploads/files/vugatazamujoto.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/fb438f40f82eb2643c67e618383d3831/6509376574.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/51299703089.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/rojirevivizivonukaxe.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/raxawudesekoboxupewituluv.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/74049140222.pdfIn PDF document text
    • http://riverside-plaza.com/upload/userfile/files/76228575912.pdfIn PDF document text
    • http://novichiha.ru/pic/file/bubimitevitoxakifelupafu.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133443bdf597---xebazelif.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29381d84cc---pabuw.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d537ebba1b---guzedozuzamujosurukanat.pdfIn PDF document text
    • https://tenfci.org/userfiles/file/71491545793.pdfIn PDF document text
    • http://score1forspencer.com/clients/4/45/4587145e2679cb7673d0e21b436e5c25/File/nepolamajegidojapa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=someone+anyone+something+anything+somewhere+anywhere+pdfPDF 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_off0000f259.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF259 18300 bytes
SHA-256: 2d6b4d8fedd2e171b0f9770558d54ba83f97079dd2566cb666a4c652f0d14b42
font_01_sfnt_off000121d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D6 11172 bytes
SHA-256: 0938f555e4180f9686ab5d03d8f14ad4b38fab1b360b455a62bc96ba12b66997
font_02_sfnt_off00013ba5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1