Malicious PDF — malware analysis report

Static analysis result for SHA-256 3913997db45b2b8a…

MALICIOUS

PDF

72.6 KB Created: 2021-09-05 15:53:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 33cd3a9cbf412d964be7f72ad0792ac9 SHA-1: cf5170bd868fa04faa264f8b12cac76e6761a51e SHA-256: 3913997db45b2b8a582708ee029454872987074bf1b1250f268f5d9273d602d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

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 https://irlanc.ru/uplcv?utm_term=4+syllable+words+list+pdf PDF link annotation
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf1bebc379---25471814224.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f52225a28---26832581749.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/4vjv92hv0r651ga4gudpkeafka/pukifibunituruka.pdfIn PDF document text
    • http://delannahotel.com/user_img/file/52958759279.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091fca19edfb---69298339192.pdfIn PDF document text
    • http://15fratrowreunion.com/clients/2/2b/2b18ccadde375fd95e9ac2d5db5aaa67/File/51878611708.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/81d7e9ff903246ff57f0de23cf1355ff/kumijujaxerusom.pdfIn PDF document text
    • https://mps-india.com/userfiles/files/71454041840.pdfIn PDF document text
    • http://transinfosoft.com/userfiles/file/gujewiri.pdfIn PDF document text
    • http://beergolfers.com/blog/images/file/sologifawamuwubovasatok.pdfIn PDF document text
    • http://formel1vermietung.de/userfiles/file/82386342678.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fddacb268d4---faxanelaw.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/bajoju.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/db4e492ed5ede6d55f9d4437a76d78f5/63133337770.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c733f9480f---13951636221.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/rolisaj.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/a31885658d24ee30a3a3039eba832f41/39624901207.pdfIn PDF document text
    • https://www.hasmow.com.au/application/third_party/ckfinder/userfiles/files/75245947901.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/o3igub85j98fl0vaor00rjh1n0/nilinebawumuzubasa.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca11baa687---37198386575.pdfIn PDF document text
    • http://fxmeat.com/upload/file/7d6ff9b7c1fbad562248cba2b619ba7d.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/2c865e87f4d2772e73cb0db52c98870a/vujavifow.pdfIn PDF document text
    • http://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/lodenutilimuvi.pdfIn PDF document text
    • https://tidurmalam.com/contents//files/46045858904.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/42531666041.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_off0000bb96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB96 15972 bytes
SHA-256: 76313b91d4da801cd5ae872abcb38f3dcbf062308f7feaa9127c2755c6456d09
font_01_sfnt_off0000e46a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC81 10708 bytes
SHA-256: 8c9f5507c76530c81e0947dde292fa2a1a43ed0e82383dc84ac3c30411e5e54b