Malicious PDF — malware analysis report

Static analysis result for SHA-256 1683924d7fd2065d…

MALICIOUS

PDF

76.2 KB Created: 2021-06-22 21:10:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: d888cdf1a4cf89bd21b007be351aedea SHA-1: 689bef325655563314ac4a1d77f702cdb1c86b48 SHA-256: 1683924d7fd2065dfdbe3266b6084d9ac5b7b1f4ee0b5acc53841b9b6adb9750
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm or redirection mechanism to phishing or malware sites. The presence of PDF-specific heuristics further supports its role as a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krisoc.ru/uplcv?utm_term=%25D0%25B5%25D0%25B2%25D0%25B0%25D0%25BD%25D0%25B3%25D0%25B5%25D0%25BB%25D0%25B8%25D0%25B5+%25D1%2581%25D0%25BA%25D0%25B0%25D1%2587%25D0%25B0%25D1%2582%25D1%258C+pdf PDF link annotation
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a33a02788ff---zazodomajalokobosugaz.pdfIn PDF document text
    • http://moto-bike.pl/userfiles/file/basirulopuzumun.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607616ef336ab---tiruwogizetebuv.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/6b6d788c73a2c001f2273c5a10dbe0d1/muwimifox.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/7b5dba4fdb06b6b9c6a9be7d36118cb6/88460687281.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607bcc9e18334---27350203714.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/fccd3e93849b80a29671f7444ac02b3c/repopibukotolifisudo.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160798c9b30c53---40740560991.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/511lmocd1nsqg6vd45m7gu4dvt/famukerodutu.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608628b7984a4---lakorofadikovadutomu.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb2bdc938fa---9486938165.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5652c5caac---rokisunepakavewutam.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/90972870241.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e6d2bfc3c---97274639021.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/7b3089a6564e5895d5ae7e394c01053f/nurewuxoziwewitutufepu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE112 5640 bytes
SHA-256: 1cb9721e6b6b538b488582062a271ba64a6002e6badfaadf24fbf3d5f4465c0e
font_01_sfnt_off0000f42c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42C 14744 bytes
SHA-256: 010ea81ce77972c0fd45d266d52a1ae82f5cc80ee4fb70bd73563ee2522e776b