Malicious PDF — malware analysis report

Static analysis result for SHA-256 42c7b7318c274ec1…

MALICIOUS

PDF

90.8 KB Created: 2021-07-07 19:36:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7d0cf75121d694cf63cb0d2d747b0506 SHA-1: 717c12653381bb65217e2fd34f9738424e1fa7d7 SHA-256: 42c7b7318c274ec17408e98521357fe2b2ba6691c81f6e369ad742bacd249055
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics identified the PDF as a link farm pointing to compromised WordPress upload directories, suggesting it's used to host or distribute malicious content. The embedded URLs, while some are marked benign, are part of a larger pattern of redirection to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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 http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16094bcedb89bd---67268432393.pdf In PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c52ece8ee---womuladodujefinujasubusol.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db6b03ea7af---37624999677.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/72271220499.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/kadovasor.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c236ed07547---bedazewuzu.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160acd76597adb---68472833766.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609445bad2480---bapupetuzoz.pdfIn PDF document text
    • http://aylincinarli.com/fckfiles/file/lalibogonusizeripogiv.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/692ae7124ced0cfa271e7e6e003b84e4/58321774506.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607cebcca31b9---82352735836.pdfIn PDF document text
    • http://collegium-connect.nl/ckupload/files/zofawapakim.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/35650039177.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5d558ff72---17316541367.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/ud52j2ms3huegqsi57ngl6vvqf/funigajasumewigapem.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/834a0a173ac424ed954ac20fc7f842d5/sabokumumevefig.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160822e66ae006---kidivowa.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607af39a6023b---91018648346.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160833ca497583---xozewisij.pdfIn PDF document text
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/82113493828.pdfIn PDF document text
    • http://kopdesign.nl/userfiles/file/90589260501.pdfIn PDF document text
    • https://airtelco.com/data/users/_/email/files/52916212695.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16080d1e7ba444---1159405936.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef5236df3c---joziw.pdfIn PDF document text
    • https://aymexco.eu/ckfinder/userfiles/files/petixezuderazusel.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad95cc92e8c---dinojujikerovisefajid.pdfIn PDF document text
    • http://araonline.hu/uploads/file/49330416535.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=can+you+use+premium+unleaded+in+an+unleaded+carPDF 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_off0000ff7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF7C 17228 bytes
SHA-256: 9e340dcccfaff56467872bbe9c9ff45fd6906daa57957d5d08f66be7d94b19e3
font_01_sfnt_off00012c6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C6D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014484.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14484 10820 bytes
SHA-256: f4687efc648f12fded18bc26731a18f66461310963e7e34c6f928b22cd6da096