Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa7afed200798783…

MALICIOUS

PDF

86.4 KB Created: 2021-09-19 21:54:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2876e89e57b2116d695c8d058dd11266 SHA-1: 93f0baccaa265503ed59c14ec3c4289de17f7db6 SHA-256: fa7afed200798783a0d71604c31e5b188e3df45e26bfba39e4c462b9e51ebdf8
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload directories, a common technique for hosting malicious content. The embedded URLs, such as the one on 'brusroom.com', are likely part of this malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/9caab60ffa24a14eafd347cec3f48575/tisulodamuvo.pdf In PDF document text
    • https://martabaktelor.com/contents/files/15643163533.pdfIn PDF document text
    • http://maciejabramowicz.pl/upload/files/file/verirodag.pdfIn PDF document text
    • https://giga-tronics.com/userfiles/files/jusonamiz.pdfIn PDF document text
    • http://belv.ru/userfiles/file/durav.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/namekapo.pdfIn PDF document text
    • https://erdenetpost.mn/userfiles/files/1925050089.pdfIn PDF document text
    • https://stpm-sa.com/userfiles/file/bozedujufojofarubenomu.pdfIn PDF document text
    • http://tianfonmm.com/d/files/manuj.pdfIn PDF document text
    • https://congchung7.com/upload/file/84047036299.pdfIn PDF document text
    • http://pro-customer.de/userfiles/file/46367584203.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/1250180223.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/lesin.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/ae070d9aeba1b2e382d2145a51e11a54/sorarivabawatubipizix.pdfIn PDF document text
    • http://giaexploring.it/userfiles/files/66362676240.pdfIn PDF document text
    • http://asu78.ru/userfiles/file/sajulunavogukewomi.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161403a33273b9---24838121722.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16134db179f8e4---55016400294.pdfIn PDF document text
    • http://hz-kontejnery.cz/ckfinder/userfiles/files/30289405933.pdfIn PDF document text
    • http://suphammamnon.org/uploads/files/pejomeduw.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161470959d0fa3---78637013001.pdfIn PDF document text
    • http://nuovartea.eu/userfiles/files/43387296219.pdfIn PDF document text
    • http://spharma.ua/files/file/bomiwipixikatibadufom.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/70092913101.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/voxoxuxozeg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=mod+grim+soul+dark+fantasy+survivalPDF 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_off0000e559.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE559 20128 bytes
SHA-256: 2701466ee5a9ec2e04f048b6315b5a4c3d3b0823359671ed892207590456c080
font_01_sfnt_off00011a6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013281.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13281 10928 bytes
SHA-256: 0f6ec536a2475d4fccc063ff37543fb65ae9311e879e92130026989170581d9d