Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ef63c23869882fb…

MALICIOUS

PDF

90.1 KB Created: 2021-06-29 20:45:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 55364503bd3e812b24e9f5db69a00c0d SHA-1: 001f88c84b0e76bdb30d89953bc9560b19cbf2a7 SHA-256: 3ef63c23869882fbb5056d732227e2704d10a04bdd7a06f9c9dc6986d743f5b9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites, likely for phishing or malware distribution. The presence of external URIs and the overall structure suggest an attempt to exploit users through deceptive links, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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://inwebjor.ru/uplcv?utm_term=power+rangers+jungle+fury+weapons
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080fc3a35a1f---wexewijirejajupiguwepifad.pdf
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160847744851e0---seratefuzikivemul.pdf
    • http://21cedu.com/pds/userfiles/files/23947748061.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1c7e3950de---81384514840.pdf
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f7979f5e8---9757019234.pdf
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/ej5lod05t7675dsvujql20ha77/panija.pdf
    • https://akapacha.com/userfiles/file/91959159356.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/ee4408b8a2dde2c3f549e13a6deb4eda/xivubaluluwideten.pdf
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/a82763502dc88a39e566747378a2f5d8/37714108437.pdf
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/50943109692.pdf
    • http://skiflogistics.ru/userfiles/file/853688914.pdf
    • http://vtvxm.vn/userfiles/file/bozatizofarabazosogetako.pdf
    • https://chezgregoire.fr/userfiles/beredejapukamorobasunubu.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/fac7752ae72adc0d1dd95022c3f4937c/bofotanepuwuximipidazipa.pdf
    • http://kondicionery-ivanteevka.ru/upload_picture/file/87973340379.pdf
    • http://rw-hse-businessconsulting.de/userfiles/file/vebefilo.pdf
    • https://parklanehotel.asia/userfiles/file/52433413696.pdf
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/ehch3e0t52nbb4h5t795uqq2fd/98090361940.pdf
    • http://kbchina.de/upload/31813646007.pdf
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609478683db5a---1228090810.pdf
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608355eb7f957---21624584165.pdf
    • http://vejwun.cz/images/61357444336.pdf
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/iuadnh5pc44523pecrc9dk5i9d/39058168601.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e605.bin
9985c666134d187a37696d6d5764b0631c9079a37baff9a6132d56b1e8884a69
pdf-font-stream PDF embedded font (sfnt) at offset 0xE605 17300 bytes
font_01_sfnt_off000113d7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x113D7 16792 bytes
font_02_sfnt_off00012bee.bin
1d4ed01f0d340d4dec907b3b0c7366c2ca28ca1f816c81f74cb24a14b6da6f36
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BEE 10772 bytes
font_03_sfnt_off000144fd.bin
00b1f632e8afe72716c8bcdb76b7901b56c060d1dc0f96f3f5c1b8373b85735b
pdf-font-stream PDF embedded font (sfnt) at offset 0x144FD 16140 bytes