Malicious PDF — malware analysis report

Static analysis result for SHA-256 834b9fc81d4f7dce…

MALICIOUS

PDF

84.0 KB Created: 2021-09-02 08:44:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1b5f028dfddf70fb5533892f24f36fcd SHA-1: c6ab3e5ed68afc3123b9e056bfef137c0ce415a0 SHA-256: 834b9fc81d4f7dcee5ff2cecd63b4f60a363427f103b77eb17c602c644fedf61
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.012 Process Injection

The PDF contains a large number of external URIs, many of which point to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the extensive use of external links points to a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://garglob.ru/uplcv?utm_term=not+only+not PDF link annotation
    • http://charugarware.com/DEVELOPMENT/charu_garware/uploaded/userfiles/file/17837537519.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608de8d55ad20---lafinosazazelufokudev.pdfIn PDF document text
    • https://futuresbuilder.net/dayafter/uploadimages/newsimages/file/wunekomovotinujaparirasu.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/effa0bd7c43e0e8c2391e8da5cebc51d/95270434034.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/14853687139.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/4tsu462bg8ggmthh5iedraepbb/lufekivej.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6439110807---bidowezufutiwarujezaxesir.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ab02c481f---78632350375.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/aafe86175e3fe95eae98418f72ddef1d/67614725915.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ed993b20b06---zorajapu.pdfIn PDF document text
    • http://stalmont.eu/userfiles/file/suwudugejidobofofufalajef.pdfIn PDF document text
    • http://furniture83.com/upload/files/muguwowibejezemoxijobanid.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/vuwed.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/ipf6ue4is19uob9h9n1i3hpe2m/xumegedewivevituwemebi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091ca5e2db63---pokopugaguvidinajutatoper.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/tulilizuno.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/ffc5d54613772fe551663037d52fd8b9/42190459738.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa706e167a4---91873040243.pdfIn PDF document text
    • http://stlukesmn.org/clients/17773/File/sitisogitowivuko.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/c624d5e9d68d270f8552a4591ef09c8b/64844336464.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/92954024367.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/aa0e5e6a65f0570386d6d7c58931f1ed/43918520988.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c209bfb54ce---regip.pdfIn PDF document text
    • https://vettercycles.ch/userfiles/files/xoneba.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607d632666d79---dejexibuvosawilejotopigi.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_off0000e5d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D5 18320 bytes
SHA-256: 08fa1ab5771215067e4cb4bb9030eab8d1b2d4d582063bcb8e2639935255a568
font_01_sfnt_off0001155e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1155E 9540 bytes
SHA-256: 44ca5afd65f85491898e17e518c6953b49414c7d8497f47f3ef7bee644b14042
font_02_sfnt_off00012a0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1