Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d4c56f6dcb7a4af…

MALICIOUS

PDF

83.7 KB Created: 2021-09-18 14:50:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1cc6086b372922d044106e93d3b2b781 SHA-1: aa4ab9c4a567ded03d8e89c7688a6931d00f15c5 SHA-256: 4d4c56f6dcb7a4afdc2e28efdce51f001636f61a44ffdd5d7095391febeb2ff6
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for SEO poisoning or phishing. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs supports this assessment. No scripts were extracted, but the primary attack vector appears to be the redirection of users through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://nomylo.ru/uplcv?utm_term=the+four+agreements+full+book+free+pdf PDF link annotation
    • https://cyklo-wellness-penzion-palice.cz/content/81156265061.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16130440c8d617---sokokefikejorizelapuko.pdfIn PDF document text
    • http://ternovykh.ru/content/file/58093831524.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb704bdde9---88016226260.pdfIn PDF document text
    • https://fivetc.vn/uploads/files/60836980249.pdfIn PDF document text
    • https://kaskad-74.ru/images/uploads/wanusimek.pdfIn PDF document text
    • https://kamionosnyelvlecke.hu/userfiles/file/90350890627.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137e570b128a---sugud.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/ca7967b2c4e1ea80a9d0f226b7461d0f/nofopex.pdfIn PDF document text
    • http://metalzilemboeventi.com/userfiles/files/suwolutajuxijalatamek.pdfIn PDF document text
    • https://dpdpunjabi.myskoolapp.com/FCKeditor/FCKimgUpload/file/xutexasev.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/5201ba0aa3c46636814e7451b4441cd1/61692783390.pdfIn PDF document text
    • https://drakbera.com/ckeditor/ckfinder/userfiles/files/vununujepavuxa.pdfIn PDF document text
    • http://lamekatus.com/uploads/ckeditor/files/fewuzolidubi.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/27565801150.pdfIn PDF document text
    • http://taiwangallant.com/uploads/files/202109071902231294.pdfIn PDF document text
    • https://easy2ticket.com/upload/files/72652477664.pdfIn PDF document text
    • http://mygiftltd.com/userfiles/file/40223925124.pdfIn PDF document text
    • https://creativitagh.com/pevron/www/img/file/93608490557.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f732ea7ce---serawelixufagowenunaxil.pdfIn PDF document text
    • https://huangs.tw/uploads/files/202109110513373861.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161430ad5cd220---20101137122.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_off0000e2a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAB9 17400 bytes
SHA-256: e1dc91080edc020f9021f4d5cb1e0b2ee10e40b5f29a5f8497550a6c428829a0
font_02_sfnt_off00012796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12796 11148 bytes
SHA-256: f9e1788d3d4da394afa130445cb98142102da45421320ba2800bb0ba1d9e71be