Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac140fe839d404bd…

MALICIOUS

PDF

87.7 KB Created: 2021-07-18 09:54:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6b02f6fb143f6d4b86df815e0b098639 SHA-1: 8450eff374506163ea0437e15e5d2bd883db0992 SHA-256: ac140fe839d404bd979c062c2004a7f81a23482315e8d63a9d79019f1233832c
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories and other potentially malicious domains, suggesting a link farm designed to redirect users to malicious content. The PDF structure itself appears to be a lure, possibly for phishing or to deliver a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://bezagsecurity.cz/userfiles/44468530079.pdf In PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/b77842c4b4eb0a4f4d8d215d5f54ec96/94348233525.pdfIn PDF document text
    • https://shopabrang.com/images/files/78361235171.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074122940f57---62655199842.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/d7fe60f18d37e73300d1d7c3d2c03df8/mawobidavu.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/temujarojafo.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1608eb87fc20e4---99853549128.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/33fb0ad06e70f9a47c0db13832893381/puwag.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/6b1a98ea0de134c4d7a1ae09aabb9bee/63074767361.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160887d552aa29---98326788986.pdfIn PDF document text
    • https://cicadit.ro/UserFiles/file/58804869121.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.com/upload/files/82304119276.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d25a7f3d79---jowekikanenebuxalu.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/10031875f19a75c4d4a5923a58e5d548/32710798647.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/kopikekemupanuradetopi.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb24eae112---zarekonatofuvikobakebe.pdfIn PDF document text
    • http://99hospitalitygroup.com/ckfinder/userfiles/files/mugesutewurabajad.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ada8171d870---roxapinabizuzuwisuwedosa.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/7261464829.pdfIn PDF document text
    • http://ingpoggi.eu/userfiles/files/jepiposimibibotusesoraso.pdfIn PDF document text
    • http://nzmbc1611.com/clients/e/e6/e6eb4f38db7021b04b945082fca6026d/File/8437360965.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/monarunis.pdfIn PDF document text
    • http://dienmaythanglong.org/uploads/files/94977514613.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1609c95c78042f---pejaxeki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=what+does+pet+peeve+meanPDF 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_off0000f44f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C66 10480 bytes
SHA-256: 11681bfe9199a448207567fcb9dc31fbe3971ea679b358c3f1e66d4e18e8a3f1
font_02_sfnt_off0001240b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1240B 16952 bytes
SHA-256: e9ac8d364df69a366c8c12e4c22af3a142cd116154283475373e82abe6e40554