Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d6f5ec91f45d4a…

MALICIOUS

PDF

80.7 KB Created: 2021-09-13 07:49:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a5375367d47b8c095848bb8b7c10e067 SHA-1: 463622e0ab06ed4618bed8d2e06f56303e54b4c8 SHA-256: 81d6f5ec91f45d4a6d1cbe856efd48e6618675489084760ec9b74b8ac0bbeb1e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable hosting, disguised as search results for popular software. This pattern is indicative of a phishing or malware distribution campaign. ClamAV detection and ML classification further support its malicious nature, suggesting it's a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://huntic.ru/uplcv?utm_term=call+of+duty+mobile+download+apk+mod PDF link annotation
    • http://watthaistuttgart.de/userfiles/file/18277968155.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e05fc07a8b---66776037179.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138ba192955a---46210971527.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e479c3a380---88561701004.pdfIn PDF document text
    • http://alvitraders.com/files/rawut.pdfIn PDF document text
    • https://ubk-sad.de/azubi/userfiles/files/95111866254.pdfIn PDF document text
    • http://www.ujepites.hu/userfiles/files/13970544446.pdfIn PDF document text
    • http://unionnutritech.com/upload/files/32440005042.pdfIn PDF document text
    • https://www.xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/vukimukunotararisijura.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/19363617188.pdfIn PDF document text
    • http://mebco.ru/images/file/vofexemivaloxunupoger.pdfIn PDF document text
    • http://actinq.nl/upload/file/55267850344.pdfIn PDF document text
    • http://pxmonastery.org/CKEdit/upload/files/rolefajejofetaru.pdfIn PDF document text
    • http://tourgrodno.by/images/content/file/26008096519.pdfIn PDF document text
    • https://bank-kredit.at/ckfinder/userfiles/files/38488064732.pdfIn PDF document text
    • http://bernendorf.ru/userfiles/file/55140850529.pdfIn PDF document text
    • http://preiswerte-unterkunft-papenburg.de/mediapool/35406536923.pdfIn PDF document text
    • https://producedepot.us/userfiles/files/47415612413.pdfIn PDF document text
    • https://icbacademy.com/upload/files/34397439039.pdfIn PDF document text
    • https://nergizleryapi.com/image/files/mesegiwunuva.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/15231667303.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/34993311843.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_off0000d7a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A5 10952 bytes
SHA-256: 429f06847510e54b3278514419463487317283a7d520548160d5770b2f1ef34d
font_01_sfnt_off0000f0eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EB 17072 bytes
SHA-256: 7457a45a4201a4ea704472335b58e7e2580e009e73a4a9cc62cb31a038123c4d
font_02_sfnt_off00011d19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D19 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1