Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbc4c857711ed4a2…

MALICIOUS

PDF

158.9 KB Created: 2021-07-07 02:12:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 8c7695171be59dbdd03c5e146494f4c8 SHA-1: 81d86cd8ee8c08d6ee25b9f40d1f85a62b52fb6e SHA-256: cbc4c857711ed4a22f4002995227da0a86836bd7e6d0aae090fde3bb8596df68
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm directing users to multiple external URLs, some of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests a tactic to obscure the true destination by using many distinct hosts with few links per host.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://cmtdental.com/upload/ckimg/files/ledilefiwenabowesibiza.pdf In PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/1e4d47b5fe6637a2f17f7e45c0b2e56c/10092907820.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7aea82b99---49047184995.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/27d4ecdd1379350bfd0cb0530be63c93/72252046585.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/0lmlgncu8lvvtv0km37lg5bl40/damatekupeje.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/fixegewazabujimiji.pdfIn PDF document text
    • http://planetamama.ru/files/file/binerawiwadiz.pdfIn PDF document text
    • http://ladyvenus.it/userfiles/files/85689922601.pdfIn PDF document text
    • https://info-jimukyoku.jp/lot/upload/files/godolatugevufuwijogug.pdfIn PDF document text
    • http://zaragozalawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/81689585143.pdfIn PDF document text
    • http://dogalakustik.com/depo/sayfaresim/file/gunitopamemujinedima.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/78ffaa3318986c0cb89a66744243503a/12450548710.pdfIn PDF document text
    • http://tizianaiberti.it/userfiles/files/21246167050.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/57902853635.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e441971ebe0---30455662354.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/gosedozanalu.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/3263565208.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/3a20a39f8b4228438b8788498105e15c/jobarebalufovuxeduworopa.pdfIn PDF document text
    • http://maxbrio.kr/files/files/loludup.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/4d0c4d3f350d9544a2e8ceae40fd5791/sivolezaruputu.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/6f20f1f30d8460223010594b6032e22e/2788487985.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160877ae753ed1---99145548485.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/rusasamosirizabororu.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c5909224440---wumarexemurojisewotilufe.pdfIn PDF document text
    • http://bluekeydigital.com/images/pic/file/77164272923.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=charles+darwin+expeditionPDF 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_off00020c4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20C4A 18876 bytes
SHA-256: 2b45fa131e4d7f33a152e6321fc82c4d53d351feb61c4f9358fe28958a715021
font_01_sfnt_off00023d1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x23D1C 10708 bytes
SHA-256: c8068a00822bcca8d0c29b8b62c348e0f23f4afc81d9b39990af24dd0b535ee2
font_02_sfnt_off000255b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x255B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1