Malicious PDF — malware analysis report

Static analysis result for SHA-256 273a0f84d3359cec…

MALICIOUS

PDF

82.4 KB Created: 2021-09-05 16:11:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 24f6b1396a564f0a6c0f27592ea9e953 SHA-1: aae7cf07f0cc57e31fee3f707c601e578dca6a5a SHA-256: 273a0f84d3359ceca2189bc0441cee2c6c20492101267090a5a65ede414bd435
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It functions as a link farm, containing numerous URLs pointing to various websites, many of which appear to be compromised WordPress installations or disposable hosting. The primary purpose seems to be directing users to potentially malicious sites, likely for phishing or to download further malware. No scripts were extracted, but the heuristic firings strongly suggest a malicious link distribution pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://chcial.ru/uplcv?utm_term=vestige+6%C3%976+plan+pdf PDF link annotation
    • http://erbamedica.org/userfiles/files/78125147211.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1606d24ebb6d1c---nuzexojusuvumegedud.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9d1494114---kosadota.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/47166439093.pdfIn PDF document text
    • https://robertbah.si/files/file/4709933309.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/41909290756.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160818f83dddc8---24631184553.pdfIn PDF document text
    • http://tplustech.com/images/ckeditor/files/setosobezogomana.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/23048403480.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/tovukozivulez.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adab4df2a18---58910806044.pdfIn PDF document text
    • http://yuha.be/_files/file/libagakuji.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a97ff828e87---pozejimukavaveguz.pdfIn PDF document text
    • http://www.terresdescaraibes.fr/file/75113631008.pdfIn PDF document text
    • http://annabarons.lv/files/files/81436937955.pdfIn PDF document text
    • http://highlandhighclassof1962.com/clients/c/c3/c330a44b04b080977bf299ea430a317d/File/8525076989.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160861fa9ae109---26244520836.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/81534334170.pdfIn PDF document text
    • https://sharadsangam.org/UserFilesTwo/file/10796030746.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/1h6ogmbeinn8mp5qs52cavv160/kewuwul.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/81809329187.pdfIn PDF document text
    • https://rumputhijau.com/contents//files/fofaxexalejenaguzuja.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/nifawuxi.pdfIn PDF document text
    • http://jkbprivateiti.com/userfiles/file/9766791824.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_off0000d8b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B3 10664 bytes
SHA-256: dcb3bb04e50e0c0fc01f00eb4fe71b86fb157dbf8c38185cfef64e013ae18922
font_01_sfnt_off0000f11a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF11A 19128 bytes
SHA-256: 87dbed289ef8d02dee990b60ff9516393d1951cadcf0834faa22e5095c6515ac
font_02_sfnt_off0001228f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1