Malicious PDF — malware analysis report

Static analysis result for SHA-256 b41851902b5f8c07…

MALICIOUS

PDF

82.6 KB Created: 2021-09-08 01:52:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 64f48ba3c7388400bc33404db9e0f7cc SHA-1: 683b7876869042b760bdcf6db9a03aca37a361b6 SHA-256: b41851902b5f8c07c298f4e489ba0a0596986cfbefe16683cc91c9195785506c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a machine learning classifier and ClamAV detection. It contains numerous external URLs, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of embedded URLs and the nature of the heuristics strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://huntic.ru/uplcv?utm_term=literatura+greco+romana+pdf PDF link annotation
    • https://mintowncoffee.net/uploads/images/files/pogepapu.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/10399475870.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/94710183475.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/74897184670.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/65485742304.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b8d454102---migexupagimikomowogopomu.pdfIn PDF document text
    • https://emauto.lv/index/images/up/file/53243917121.pdfIn PDF document text
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/1fbkjhgdqa5795qohc3a1htudq/28217237237.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/mutelevinunonabosowu.pdfIn PDF document text
    • https://brod-plovdiv.com/images/ropibotiga.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/51365570d2fbf6e42a1db7013b17c5f9/83902349152.pdfIn PDF document text
    • https://mamo-tato.ro/userfiles/file/fafipimajanu.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/a4d2b5f0cf00390288b666366955c07b/63062312946.pdfIn PDF document text
    • http://mosjob.ru/images/file/rabujevura.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/68975146792.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/zovijogebozebuva.pdfIn PDF document text
    • https://sevenhillsgroup.net/ckfinder/userfiles/files/56109282280.pdfIn PDF document text
    • https://saunadlaciebie.pl/userfiles/file/9816411223.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/55724624409.pdfIn PDF document text
    • http://chothuexeninhbinh.net/data/dulieu/files/fidodufaserumejadajemura.pdfIn PDF document text
    • http://www.ferm-matic.fr/upload/file/85931345940.pdfIn PDF document text
    • http://eko-inwest.eu/upload/file/28110834781.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/89293963155.pdfIn PDF document text
    • http://faceconnects.com/ci/userfiles/files/xoguvexizuzi.pdfIn PDF document text
    • http://thailaundry.com/imgUpload/files/debogejejegegomawekemojom.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/vetogiwububewebosez.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_off0000dbed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FF 18528 bytes
SHA-256: 7a4a8b112c6c0428d72b85755e2c04f1311e18699bfe5585cf98b4cb4b7f6d34
font_02_sfnt_off000123dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123DC 10804 bytes
SHA-256: d5ffeeb0b34a89f3840eafac4b3650a474fe5e02677ee3ff398d5f935cee2351