Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c9836c851a67b3…

MALICIOUS

PDF

88.0 KB Created: 2021-06-27 04:50:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 544fc96d87900a8c0663ef210d5c10dd SHA-1: cf7b994d4aa472303757ed3d0e40f15149d56ecc SHA-256: 28c9836c851a67b3888013dc6a4ba18c09d77c501fd13ce53f049efc41846b88
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to distribute traffic. ClamAV and ML classifiers flagged this PDF as malicious, specifically as a phishing trojan. While no scripts were directly extracted, the nature of the link farm suggests it's part of a phishing or malware distribution scheme, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/da3f248991a7a2cbc055f4afe5be6402/watosesewumabuzativurivo.pdf In PDF document text
    • https://gyandeepjkss.org/userfiles/file/70668728668.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16075352ff1c18---2130699993.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b63b19b9695---sonazinew.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3495a0ce6---46891048464.pdfIn PDF document text
    • https://pui-vital.ro/msg_media/file/tolidu.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c066025015c---gowopasefogunukolalurobin.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/futupolonifiberotadiluxuf.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609a024abeb87---10148122515.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/2197375117.pdfIn PDF document text
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/968514c2c17c6354b3c3d55beea884fd/48943034812.pdfIn PDF document text
    • http://greaterdeliveranceministries1.com/clients/61527/File/vutegadudinabubufupowexe.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16077d49e9ab1d---kajujulipokobukowademiwe.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/1b2b73826332de0fa16fced7f04078eb/65128345073.pdfIn PDF document text
    • https://alutat.com/data/file/remigugotepabodud.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbba35529f2---33953804245.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/rubadixefuj.pdfIn PDF document text
    • http://ketnoikienthuc.com/upload/files/golewozolizizijazito.pdfIn PDF document text
    • http://servmed.net/userfiles/file/rivitug.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a19a9d69aed---nudixafofur.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160aa554e1e93f---7372768449.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16088b80a95daa---maxafuwofilexosagi.pdfIn PDF document text
    • http://studiofapas.it/userfiles/files/badegugezozaketuziwak.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16071c3f21d948---zutasanosopoluma.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/88oatubgr2h5c0r19adr15d0l5/wepepilefesisuv.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/v1j43lestbk2dhd665v7b0pjat/guvewabami.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=list+of+most+profitable+small+businessesPDF link annotation
    • 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_off0000f3c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010bda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDA 10716 bytes
SHA-256: e7e4cab15f0ce3622af8c24b37417a7396f5c71693c60985b437bff5f6543c14
font_02_sfnt_off00012433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12433 18140 bytes
SHA-256: e3c5ceedaca932ce75368c8cbeba85c1aa70fbf162d2ef26222de4f5b10ea7c2