Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb50a288c704d1db…

MALICIOUS

PDF

82.3 KB Created: 2021-09-10 22:04:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c74c3bff77e15ffa60762a95c5d0cfbf SHA-1: 685d0c9c32a11e09110b6893dacd9d7fb1d2ce7a SHA-256: bb50a288c704d1dba7e65d13c986887b16f9049468a6903ac7debed6d95c6d1a
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress uploads or disposable hosting, suggesting it functions as a link farm to distribute further malicious content or phish users. The presence of external URI heuristics and link farm indicators supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://drafthe.ru/uplcv?utm_term=video+maker+app+for+laptop+free+download PDF link annotation
    • http://thechitay.com/uploads/userfiles/file/datukuverowinovorirebo.pdfIn PDF document text
    • http://minhanh.com/files/romorowevadevokazevav.pdfIn PDF document text
    • http://tucsokszekszard.hu/images/news/file/dewarelizefu.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/mukakizajirexunepagon.pdfIn PDF document text
    • https://breedlife.com/upload/files/44756899684.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/kenobowetesi.pdfIn PDF document text
    • http://mixline.ru/img/lib/file/36182402884.pdfIn PDF document text
    • http://xsjsbzrw.com/uploads/files/90813045947.pdfIn PDF document text
    • http://fuerst-architects.com/uploads/file/vuxudofibovupenujirofisij.pdfIn PDF document text
    • https://franchiseharbor.com/files/files/ligebuxevidumakipasatunod.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/71407840236.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/waziguzer.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135d9948216f---rixita.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/dotakaberexize.pdfIn PDF document text
    • https://onecre.com/images/content/files/retuwusajo.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613343f4a1819---94081670152.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/2ca258cfcee51f42851cba84103f6ccb/49769070930.pdfIn PDF document text
    • https://andrejc.si/files/file/27113226111.pdfIn PDF document text
    • https://sananselmo.com/wysiwygfiles/file/nalajoboxapolafigudek.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161313b88ee6f0---75973993666.pdfIn PDF document text
    • http://phuquytravel.com/nguyenvanlinh/files/wuxoruzodulutisa.pdfIn PDF document text
    • https://ihappywash.com/uploads/files/202109020315521244.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/9391444705.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_off0000dcef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF506 10636 bytes
SHA-256: 340610780a1b77e076b3e77ce1b82d559387d1d92916a082423f8738b88b9593
font_02_sfnt_off00010d5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D5D 18052 bytes
SHA-256: e6028c1a7622f22dcaf764bd5f6b394a82bd0351111ef8f40f5ac10d50d1348a