Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9f2fdda7e923874…

MALICIOUS

PDF

122.9 KB Created: 2021-07-04 20:34:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 1d0d7dffe473024d2f65776027ada446 SHA-1: 34af50f3e0baad9f1f621ac7a61ee13d9dbca0fd SHA-256: a9f2fdda7e9238742eb5af94353aa041b1da3b168c0e774e45efaf64b439857f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised WordPress sites. The presence of embedded URLs and the nature of the link farm suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9788

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://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/n8shtfv2lgbccdvpb7r2718evv/gawusom.pdf In PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/39578633190.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eb6a5258f7---kibafa.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160970cfa2a343---vuvukuk.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/baweso.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/s0r50pmlpamrjo8fbkknoett6t/70124163941.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/tupexinediz.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/d8705a5bcd8cef487d3caea5148c8ae4/nazonuvi.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/34700181740.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873ca544f15---xemebuxuvomudoveg.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffaba53a27---xezevisatadoritu.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608e3f57edb19---50633236466.pdfIn PDF document text
    • http://cuacongtrinh.vn/upload/files/3821786065.pdfIn PDF document text
    • http://agisma.ru/files/pages/files/jonunavilutobibiw.pdfIn PDF document text
    • https://nisahanpin.com/calisma2/files/uploads/6439116765.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ceefe862c8---siwuziwatavenabobujufedew.pdfIn PDF document text
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/i285u52tgm1kj8chc8vvrmhq1e/xovawowexobotazud.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/79712c5c9c11660c11402ca6846b7e2c/89300968386.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/f7f44921912e416dc7b7da1a0cc023ae/71183716083.pdfIn PDF document text
    • https://tyko.pl/userfiles/file/30371532045.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffcf282214---91009862017.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d46f8e3a5---nidamizafujope.pdfIn PDF document text
    • http://retco.ge/ckfinder/userfiles/files/61223527329.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1606e67a5a207e---92062051797.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160abcc1c3a2df---33478901219.pdfIn PDF document text
    • https://condominiobrisasdelnorte.com/userfiles/file/95356880271.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2714d2d1d---60159353157.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=leading+and+lagging+strand+synthesisPDF 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_off00017ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17AB2 19296 bytes
SHA-256: dea6fcd21e594f56b0ae46b2a9563d0cc3f1abc2ef3c439b9b14075523956951
font_01_sfnt_off0001ae5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AE5C 10476 bytes
SHA-256: cc0d12711625131ce5115d6438cdd06671af2b01cfd8a2139df2e7bc5f348404
font_02_sfnt_off0001c5da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C5DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1