Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8a40112c7bd04e0…

MALICIOUS

PDF

80.4 KB Created: 2021-09-18 10:26:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: cc0cd6beaf8a0e3849206e61ec685769 SHA-1: 2849f4f139312cb5d10b96fd6573ef1966782caf SHA-256: f8a40112c7bd04e07499d9473e1bb6111fd04aec5c5ecf11602a32b2177b998b
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple external URIs and a link farm heuristic points towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://medvor.ru/uplcv?utm_term=anti+discrimination+act+1977+pdf PDF link annotation
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/kudajif.pdfIn PDF document text
    • http://skalamatbaa.com/userfiles/file/vugap.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/rpevh4h3rq38501ffomjm7s7g9/46814006886.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/lopigobo.pdfIn PDF document text
    • http://carnavaldemarbella.com/Senegal_5/Content/files/userfiles/file/43866404136.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/tefov.pdfIn PDF document text
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/34572773988.pdfIn PDF document text
    • http://fpole.ru/sadm_files/6239429046.pdfIn PDF document text
    • http://bukharaalpharetta.com/sites/default/files/file/vibakifidalaba.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents/files/lugegilefefur.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613df5dd0874f---76542760896.pdfIn PDF document text
    • http://macro-e.com/app/webroot/userfiles/files/gemet.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/69334330366.pdfIn PDF document text
    • https://adtw1.elfjane.com/ckfinder/userfiles/files/pumexobukomeduteledogun.pdfIn PDF document text
    • http://www.hausbaumesse.at/ckfinder/userfiles/files/45271379477.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/30935519901.pdfIn PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/3390209637.pdfIn PDF document text
    • http://koyomisushi.com/uploads/files/35567181610.pdfIn PDF document text
    • http://slhospital.com/upload/fckeditor/file/xajamokobifizarodu.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/94302200706.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/sosakif.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/d9a7dada8c4e1366530aa3101c669f7f/19886268639.pdfIn PDF document text
    • https://brod-plovdiv.com/images/wulexopolexovaropupuxed.pdfIn PDF document text
    • http://hitelesen.com/userfiles/file/24067926068.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/52038424831.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161322504e9aed---zugixorutarikepofugirax.pdfIn PDF document text
    • http://erago.cidees.com/uploads/files/famofalagi.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/36874807507.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_off0000d50f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD50F 17448 bytes
SHA-256: 2e125daa390ccde8c519f79f0d27d864e26cc38c9da25c24eeb097e03537bbad
font_01_sfnt_off00010212.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10212 10856 bytes
SHA-256: 2f8fe7caec17a7a7b82b8d9a3f0b3f89de471f12a3e207b6071ff94df2634737
font_02_sfnt_off00011b4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B4A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1