Malicious PDF — malware analysis report

Static analysis result for SHA-256 579d9cebda63e28d…

MALICIOUS

PDF

73.7 KB Created: 2021-09-07 12:57:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 75308b8998aa7cfb3a337380d9682213 SHA-1: 3acce85e08bf81e2854dbfe9fbbb1b60d6479a35 SHA-256: 579d9cebda63e28dc2bbbea512b4cca29cf5de8e8619d98f3a7581578901c634
96 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS uploads, indicating it functions as a link farm. The ML classifier strongly flagged this PDF as malicious. The presence of multiple distinct hosts and the use of 'utm_term' parameters suggest an attempt to manipulate search engine results or lure users to malicious content, likely for SEO poisoning or phishing campaigns.

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 https://laborke.ru/uplcv?utm_term=girl+baby+names+starting+with+k+in+tamil+pdf PDF link annotation
    • http://denge.aero/upload/files/vokuko.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607153df3b422---limejokufopixi.pdfIn PDF document text
    • http://eortak.com/img/fck_temp/file/99188153265.pdfIn PDF document text
    • http://dogoducthien.com/uploads/files/82324265434.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/69822159536.pdfIn PDF document text
    • http://winso.tw/userfiles/file/37516171171.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/29309624535.pdfIn PDF document text
    • http://ehs1958.org/clients/73155/File/79392217505.pdfIn PDF document text
    • http://phonphangschool.com/upload/files/34135604179.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ab0e8a0ebb0---79833665716.pdfIn PDF document text
    • http://www.euro-fly.eu/userfiles/files/mogivazizerete.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/riditasafugifaxolex.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/31613171ae1a216ae883b14ac03186b0/ritabaguzikosiredodeper.pdfIn PDF document text
    • http://daisytalavera.com/userfiles/files/27276514369.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095c782033a6---69064830007.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/92212529666.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/30153491300.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/bixagujuwosinez.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/413a2d5771cf611fe7bd17a659cac259/penoweliwidip.pdfIn PDF document text
    • https://blv.by/upload/editor/files/64971122038.pdfIn PDF document text
    • https://dichvuhappyhouse.com/upload/files/fopuwepisa.pdfIn PDF document text
    • http://pn-tech.net/userData/board/file/juwevekusimafofikivit.pdfIn PDF document text
    • http://e1pl2.nazwa.pl/busy/fotki/file/movuvilujimo.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_off0000bd15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d527.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD527 16104 bytes
SHA-256: b321f0956c89dea1d856d581af474893f062400ad498992d71a1a8cdbebf93ef
font_02_sfnt_off0000fea1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA1 11296 bytes
SHA-256: 196934612cb7392a83347ce2496ed2f2960524e6547bffe6f77ceb0922ecf4bb