Malicious PDF — malware analysis report

Static analysis result for SHA-256 638f403c130a6f5b…

MALICIOUS

PDF

85.9 KB Created: 2021-07-03 17:46:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 16262aa2e58742d3af91e1c049115a03 SHA-1: 087012b95607edb52c21374befe71e10890bbb7e SHA-256: 638f403c130a6f5b8f10d8b4f4e62ebc0d346fe14fb0e47874efd1636465a625
156 Risk Score

Malware Insights

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

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 hosted on compromised WordPress sites, designed to redirect users. The presence of multiple unknown URLs suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a93e201f2ba---87260590397.pdf In PDF document text
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/d96831cb3e537c8d9b2f14cc46717b82/63155376551.pdfIn PDF document text
    • https://tusenfotingen.nu/anvandarbilder/108/files/buxosixirivo.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/74958511576.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df36c1685ad---31324875735.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/25bb4e15a3f5517fd45690e4bc5ece07/34779017551.pdfIn PDF document text
    • https://adsbudget.net/userfiles/file/kowiromena.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/xizufavuxade.pdfIn PDF document text
    • https://thaiwoodengames.com/files/upload/files/vomimidisamezeg.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e48fef292---mepujeri.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/ce987e8b4950cc8111d5f465da5368c7/polobinosik.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/finakabavuwugeja.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160bb4cc501900---wesisalivepotanovimuzej.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160857dc31809b---10036997049.pdfIn PDF document text
    • https://visionbrindes.com/admin/fckeditor/userfiles/file/tevafapike.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/uesqf616htdjuoad1po8ab04pa/73367248502.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/dudotozigexepuwibezix.pdfIn PDF document text
    • http://timelessmebel.ru/wp-content/plugins/super-forms/uploads/php/files/a25629ebed7eb3f3885aecbbd6ea51e5/11136095846.pdfIn PDF document text
    • http://93564497.com/userfiles/wifijid.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/dusonubujanozukugila.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609675c9a49ba---88863009077.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609a9e66280f6---jonekuv.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/fe6026fc676b8a3cc7ff7e6aa9208466/81363168396.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4f1f28690---subogisulaviwinixopadem.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609b2612e49ab---pobezezifewodon.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=netherlands+in+frenchPDF 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_off0000e8f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F4 18500 bytes
SHA-256: d8206ff039f3c7ea55a724dfe5f30ab0a90f36fdfe5b8f230131b02fb47dfb4e
font_01_sfnt_off0001190b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1190B 10428 bytes
SHA-256: 0d83a782ede0b20235276a5cd4c01ca4dddc08b73168566ccc89b58715b7160a
font_02_sfnt_off0001309c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1309C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1