Malicious PDF — malware analysis report

Static analysis result for SHA-256 50881c5fe3c7554b…

MALICIOUS

PDF

76.4 KB Created: 2021-09-16 22:59:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9fb57efb33716c64ca4603a0d767123e SHA-1: de6d5d871f42b466eb687671f4c1b12a3b933f12 SHA-256: 50881c5fe3c7554b19ca73c31eb0c17ff78e6ada028842f59a43ea6ba55b1234
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious content. It contains a link farm pointing to compromised WordPress upload storage, likely intended to host and distribute malicious files. The presence of external URIs and the nature of the heuristics suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://krisoc.ru/uplcv?utm_term=download+secret+neighbor+android+apk PDF link annotation
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/161417d604cf86---welivunojaxulasifipibi.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/sowiwuvupevivod.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b6e008bb30---26900958456.pdfIn PDF document text
    • https://mcdelandes.ca/uploads/file/71385813434.pdfIn PDF document text
    • https://sysyanginguvenlik.com/uploads/files/61902208369.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/89304196890.pdfIn PDF document text
    • http://podwierzba.eu/ckfinder/userfiles/files/dunimexapi.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents/files/69555389851.pdfIn PDF document text
    • https://shibbirs.com/media/files/lilunonosudefeda.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/zigugigajereputonate.pdfIn PDF document text
    • https://smartcrm.cloud/upload/files/38606215699.pdfIn PDF document text
    • https://ccs-corporation.com/ckfinder/userfiles/files/95148956352.pdfIn PDF document text
    • http://anshan56.cn/userfiles/file/1631074163704438760.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1613d558a74dcb---18800863237.pdfIn PDF document text
    • http://debeight.net/UserFiles/File/rigapiwavaramorulimowuku.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/39704973379.pdfIn PDF document text
    • http://lulanjina.net/upload/files/sezenububobaxesog.pdfIn PDF document text
    • http://ilsungwarehouse.com/userData/ebizro_board/file/96714256801.pdfIn PDF document text
    • https://eastmanllc.com/ckfinder/userfiles/files/vizeso.pdfIn PDF document text
    • http://www.cavice.fi/tiedostot/files/96645671223.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210902093754.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/gaxerononifa.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/kuriwitoridesapenuniseg.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/24440518633.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_off0000c9f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e20c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20C 11112 bytes
SHA-256: be0cbbe66db2e9f04382c1decb76c74b9bd9046dcf18fc07fe45778c73406a04
font_02_sfnt_off0000fb86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB86 15800 bytes
SHA-256: c4617e0530bfce801ff2a18e7c956a1ab761bfd34f9b54b14d56546eb8f2548d