Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8eb59b532dea5a4…

MALICIOUS

PDF

79.7 KB Created: 2021-09-02 12:54:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c6c416d8e51e71a2413dfa4e5e2552ca SHA-1: 40e67ff3cc69f8644e1b526ec68bca893586d89c SHA-256: c8eb59b532dea5a45a92866fafe5ec45056c507326dbb417abd9928ac3418170
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and distribute links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=vcm+200+pdf PDF link annotation
    • https://szabobuszberles.hu/files/files/zivotewi.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b12171864---maliji.pdfIn PDF document text
    • http://beijinghuojia.cn/userfiles/file/56482356616.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1610ac55463f7c---rubedanuluwunuwixi.pdfIn PDF document text
    • http://www.odnpoznan.pl/fotki/file/file/benixaxufewosizukiziboxo.pdfIn PDF document text
    • https://samarthanamparisara.org/apadmin/uploads/userfiles/files/pejoxewesetobewux.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8b52e31f7---40327209262.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/bvhsvq2sdsiku6qoo5vrlefil3/dorigeferugogonudi.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/89929ab991c0734c6f9a42bf5085a61a/29428358094.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612c60a802b79.pdfIn PDF document text
    • https://sanaspinler.com/calisma2/files/uploads/pikubuvesitumeti.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/wugukuvel.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/lepizigekurajopopif.pdfIn PDF document text
    • http://jevades.com/aircraft/fckimages/file/wunosaxumotaxeruriwopuxe.pdfIn PDF document text
    • https://fcr-fomentoconsumoerenda.com/uploads/files/jonefomowubi.pdfIn PDF document text
    • https://mytalk7.com/_UploadFile/Images/file/zarexuxajafi.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/zomokuwemulepenusapoju.pdfIn PDF document text
    • http://millecolori.it/images/file/4781988531.pdfIn PDF document text
    • http://jsushibrea.com/uploads/files/45893129715.pdfIn PDF document text
    • https://study4student.com/cache/fck_files/file/30801287937.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/na3m6c3spat6ss7tf43225acc3/23364624234.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/jufewuporobas.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/dd79afad4b0454ce6b15a0d498d4e1a1/tepap.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/kowitugojexosebam.pdfIn PDF document text
    • https://aedwea.com/upload/foto/nufuxiwuwitodiva.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bda992f898---41197849021.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_off0000cdb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C5 20584 bytes
SHA-256: 6d4348a87d55c2812b5a440804fc155ee0124bac8c96d7e0c60d9260d0317a69
font_02_sfnt_off00011b73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B73 9972 bytes
SHA-256: 1e464d0a80df94c401165eb0aa81820cb44608ad860729df85ab57ecf445a93e