Malicious PDF — malware analysis report

Static analysis result for SHA-256 49f81fe31ebbeec1…

MALICIOUS

PDF

82.0 KB Created: 2021-09-22 12:57:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 018553d73b9f14332b10f1312ff10b55 SHA-1: 7ac011882a1c18a4b4d8a3f2096ee46144c9c5c6 SHA-256: 49f81fe31ebbeec176da989e3913868cd2361872e3fb5b53f8a3987af4e1b5be
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many of which are associated with link farms and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://pixomot.ru/uplcv?utm_term=couch+potato+android+app PDF link annotation
    • http://luyenthidhcanhsat.com/Images_upload/files/xujadopu.pdfIn PDF document text
    • https://amatnieks.lv/pictures/image/23553637756.pdfIn PDF document text
    • http://mbeautyconcept.com/upload/content_images/file/75972929663.pdfIn PDF document text
    • https://liepasmuiza.lv/userfiles/library/83806406456.pdfIn PDF document text
    • https://www.serwkom.pl/plugins/ckfinder/userfiles/files/wozekuwebozokolunelafulo.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/dosibipotetepadukozu.pdfIn PDF document text
    • http://koppeika.ru/userfiles/file/48256519809.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents/files/gagorejefomomurulat.pdfIn PDF document text
    • http://www.yemany.com/yemfiles/files/88582490655.pdfIn PDF document text
    • http://katela.net/userData/board/file/kawebatosikowe.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614871cb95d0f---gerapuliburanepanuwu.pdfIn PDF document text
    • https://maisonforville.be/documents/file/48955022508.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/79228705839.pdfIn PDF document text
    • http://podhoru.cz/userfiles/file/38892989164.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/turotureronege.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/43183050436.pdfIn PDF document text
    • http://wwm-quanta.com/upload/files/wipovixaxu.pdfIn PDF document text
    • http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/jefixuratodomimunowerel.pdfIn PDF document text
    • http://montex.pro/uploads/userfiles/file/sowuwoviju.pdfIn PDF document text
    • https://pleasanton.com/wysiwygfiles/file/13195662931.pdfIn PDF document text
    • http://cbestdesign.com/ckfinder/images_store/files/12312708225.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/59344146131.pdfIn PDF document text
    • https://sistemagestiondpr.com/userfiles/file/maxemevukisepuvanadow.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/pigexemizupidaxek.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_off0000dbfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFC 17660 bytes
SHA-256: 509d5417706fe2d1af0b662a8e247c0279ef417f9868d953ee1b03c0366ff683
font_01_sfnt_off00010a97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122AE 10396 bytes
SHA-256: d7b091c32afe5706150ca41f7a2b26d1085be559cfd4a3ff504e9e640eff8102