Malicious PDF — malware analysis report

Static analysis result for SHA-256 89c771d813bff8b7…

MALICIOUS

PDF

68.8 KB Created: 2021-09-28 23:04:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7221acc88fa695961b0995c07b30eb27 SHA-1: c406896b940f3f209c8a9beefefa38d224557e08 SHA-256: 89c771d813bff8b73384772c4cf82d42d8f6e4b805b881a647d172b9d7e43fa2
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised websites and potentially malicious files, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://laborke.ru/uplcv?utm_term=how+to+move+obb+file+in+android+11 PDF link annotation
    • https://nocnepal.org.np/ckfinder/userfiles/files/83796006415.pdfIn PDF document text
    • https://euronuts2009.ge/files/files/risawiwunememito.pdfIn PDF document text
    • https://pcparts.fr/ckfinder/userfiles/files/50004761826.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614348f3588b2---bagopolapanimijoj.pdfIn PDF document text
    • http://snkpost.com/fckedit_file/file///20210904_23_50_9.pdfIn PDF document text
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/5648434205.pdfIn PDF document text
    • http://hyswimpool.com/userfiles/40153223989.pdfIn PDF document text
    • http://cavusofis.com/images_upload/files/5756212272.pdfIn PDF document text
    • https://aiaciran.org/cache/fck_files/file/zuxerekizumikelo.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147290e44341---niseba.pdfIn PDF document text
    • https://huuphongplastic.vn/uploads/images/files/52138704991.pdfIn PDF document text
    • http://www.agot.pl/upload/file/fuwanojoziwavofeda.pdfIn PDF document text
    • http://wmc21.com/ckupload/files/22400603315.pdfIn PDF document text
    • http://marienoellebermond.com/img/uploaded/file/fefikisifivi.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/40802211843.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146fcaec1ca1---bozukinutub.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/kukonub.pdfIn PDF document text
    • http://katela.net/userData/board/file/43168883596.pdfIn PDF document text
    • http://arredamentoambienti.it/img/file/32994315925.pdfIn PDF document text
    • https://rivieresoceanie.com/userfiles/file/makidolaborerebaw.pdfIn PDF document text
    • https://zakazspbwatches.ru/upload/files/faxipiw.pdfIn PDF document text
    • https://fundacjanadzieja.com/images/wyswig_images/file/zuwotiz.pdfIn PDF document text
    • https://taperagi.com/contents/files/derogasikero.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_off0000b05b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB05B 14568 bytes
SHA-256: dfa9b86981c1e36289fb1cf97a428d20f37863e99980694cabe8937fb4923b73
font_01_sfnt_off0000d4c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C6 10684 bytes
SHA-256: fc87879ff3cc11bec326e6e64001f46fab6bf99ce4c4c243b4017fd5bed0bf99
font_02_sfnt_off0000ed40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1