Malicious PDF — malware analysis report

Static analysis result for SHA-256 c85ccbde559bc3f5…

MALICIOUS

PDF

77.2 KB Created: 2021-09-24 20:21:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6f2eb299889cd1b5b01b4bb44bdbf921 SHA-1: a816f5408ddc2ae72eae5bc4b55eca4d1392dd1b SHA-256: c85ccbde559bc3f57de02c0397879fc309f783e62f9f149d4847b9b9b5becd60
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URLs, many pointing to disposable domains and employing UTM parameters, suggests a phishing or malware distribution campaign. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://laborke.ru/uplcv?utm_term=ea+games+for+android+offline PDF link annotation
    • http://viviapalermo.com/userfiles/files/wolifasidimovukuduvevuja.pdfIn PDF document text
    • http://plkorea77.com/ckupload/files/80915444751.pdfIn PDF document text
    • http://xn--h49al71atridzo.com/userData/board/file/musigojumakiwurele.pdfIn PDF document text
    • https://beautydiction.com/ckfinder/userfiles/files/16417422956.pdfIn PDF document text
    • https://www.highettmetal.com.au/application/third_party/ckfinder/userfiles/files/32291720214.pdfIn PDF document text
    • http://www.forteks.com.br/admin/ckeditor/ckfinder/userfiles/Images/seresomiwaduzugevuwiw.pdfIn PDF document text
    • http://ks-klinika.ru/ckfinder/userfiles/files/37554543923.pdfIn PDF document text
    • https://thefertilizerproductionline.com/d/files/71155207669.pdfIn PDF document text
    • http://strap.sk/uploads/file/koxisakezevomip.pdfIn PDF document text
    • https://czus-lukasa.sk/userfiles/file/71744573042.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16143a314828a2---pozemanozabufeka.pdfIn PDF document text
    • http://inventory-acepipe.com/images/uploads/files/dusaxebiwonajuzexi.pdfIn PDF document text
    • https://sandipkumardutta.com/ckfinder/userfiles/files/72602258785.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/20861429476.pdfIn PDF document text
    • http://gaushalango.com/uploaded_files/userfiles/files/zobudifirowu.pdfIn PDF document text
    • http://www.kotolantopeni.cz/files/kafalepirozilux.pdfIn PDF document text
    • http://benetalent.com/upload/files/bubasajepozajetud.pdfIn PDF document text
    • http://chinahongji.com/d/files/75989667086.pdfIn PDF document text
    • http://velomagazin.hu/UserFiles/file/41286377291.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/juxiworiw.pdfIn PDF document text
    • http://fohow77.ru/upload/file/vuwelidowabuwifiwepen.pdfIn PDF document text
    • http://www.fashiongale.ro/userfiles/files/kulakurukabezaxole.pdfIn PDF document text
    • https://nezamirekhaseafoods.com/userfiles/file/55655114490.pdfIn PDF document text
    • http://geraldinekilkelly.ie/67846849322.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/e064c3e36f21162895a1e4effa08f331/68711393714.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b1e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1E0 18100 bytes
SHA-256: b9dc2ab12c4758d66475ebedb3bdc731c128eccbc789b5302b85a0ef515f9ac0
font_01_sfnt_off0000cd78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD78 16172 bytes
SHA-256: c28633e81f194fe513eaefbe103f720698d6182d9bada766b82bdeafce0f38a7
font_02_sfnt_off0000f683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF683 10580 bytes
SHA-256: 7bb39a160afa23064cbe86785e7d67f2433f8c801f73cb19124c72ebd0ce4fb2
font_03_sfnt_off00010e5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1