Malicious PDF — malware analysis report

Static analysis result for SHA-256 831a830766b9f9b2…

MALICIOUS

PDF

81.9 KB Created: 2021-09-23 01:56:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: b5a98012b642727efee6d441ef2fc6e3 SHA-1: 05920bbbde18f2ac6aa367bc8ae934a1a95e6ebf SHA-256: 831a830766b9f9b2d8a56f5ba3331eeafe5d747bbbf2e4b4447da14054c723e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://wastran.ru/uplcv?utm_term=e+football+pes+2020+apk PDF link annotation
    • http://splhardware.com/UploadFile/file/2021092013103473499.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/73sv32b3fcos4cl27oec26dvdn/wisoxuwaxuzasip.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/e736d4ffbee6941c0ab829005dc88f13/75604420225.pdfIn PDF document text
    • http://101eyewear.com/luutru/files/gabokosisewerewefubuxukid.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/naziwusetad.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/sirurusebed.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/45341080502.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/kedalizewopagimanugid.pdfIn PDF document text
    • https://china-glass-mosaic.vegner.com/userfiles/files/20210903_132355.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/16218105899.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/47743952399.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/kpep3umoag3nl5befmcd1frqqn/50380426465.pdfIn PDF document text
    • http://guchen.ru/d/files/kujenofogesaxitulunarite.pdfIn PDF document text
    • http://donghobaoan.com/uploads/files/lososozuzirumejozes.pdfIn PDF document text
    • https://simorgh.it/uploads/file/98154759842.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/gowefugufarigejupilimup.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/dofavanutekowazuzit.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/26645082170.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/82697812377.pdfIn PDF document text
    • http://propack-th.com/image/upload/File/75819272320.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/72208114739.pdfIn PDF document text
    • http://lgassociates.in/uploads/37552550397.pdfIn PDF document text
    • https://seerupit.dk/assens/file/94339012319.pdfIn PDF document text
    • http://dallapietamarchisio.it/userfiles/files/8901115815.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/61876730853.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_off0000da70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA70 18348 bytes
SHA-256: be104e7b01e9a43dd5db13ca31e2527b9a0dddd3112c9c46470de09a905b74a4
font_01_sfnt_off00010a27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001223e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1223E 10512 bytes
SHA-256: f4b127bc859b6fb092dc4b7ed0e63b5d8bfd5882310ea24f45a1354fa7094bab