Malicious PDF — malware analysis report

Static analysis result for SHA-256 9796b10033151229…

MALICIOUS

PDF

85.1 KB Created: 2021-09-08 22:36:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 275ab105a11e8212507380e834857555 SHA-1: aa6b1d4c85f9cf32f5709d34664fb2fc9cedbfef SHA-256: 9796b1003315122994f825431019d0afdecb76c0562a2f04532632c5bb6b1851
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous external URIs pointing to potentially compromised WordPress uploads and disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its direct purpose beyond linking to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://catamma.ru/uplcv?utm_term=explain+osi+model+and+its+layers PDF link annotation
    • http://alvit-bk.ru/userfiles/file/sirowitulenenugukimo.pdfIn PDF document text
    • http://mobil-tech.com/files/83686260607.pdfIn PDF document text
    • http://emrc.ie/upload/imagecontent/file/19712194068.pdfIn PDF document text
    • http://dycelife.com/userfiles/file/surelivisuvuk.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210905/file/16308323156411.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/fekineniluzulifasates.pdfIn PDF document text
    • http://langmypham.com/luutru/files/kofubadituzujovip.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/b3c48557d33b9a642d1a0ced36d6ab30/94193878629.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/fonilezos.pdfIn PDF document text
    • http://townofwinslowin.com/flash/townofwinslowin.com/file/52499811578.pdfIn PDF document text
    • http://josquin-capella.de/download/30828919306.pdfIn PDF document text
    • http://bidmitt.com/img/files/file/kuwokurasomorekij.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/debiwunujubudesezuxu.pdfIn PDF document text
    • http://honderhotel.com/UploadFiles/FCKeditor/20210908114609.pdfIn PDF document text
    • http://gaudi.tw/upload/file/wazija.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161368256143a7---zuwoluwol.pdfIn PDF document text
    • http://nfc-lampang.com/user_img/files/ginavuzumaguminofujok.pdfIn PDF document text
    • https://pellevah.com/upload/files/jakiserenefitixike.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/15574347077.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/78374119177.pdfIn PDF document text
    • https://datatalk.ilvzhou.com/upload/files/2021/09/202109070330552766.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb1db26757---11843550685.pdfIn PDF document text
    • https://kudamatsu.org/userfiles/file/diluderowalixitazajixuju.pdfIn PDF document text
    • https://o2opr.co/userfiles/files/80891575880.pdfIn PDF document text
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/68236651451.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_off0000eaf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF0 10752 bytes
SHA-256: d9cbc3405b92337ec673f48177bf2f8ede255f3c63c6e58acb265eb76298dff4
font_01_sfnt_off000103ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103AC 16576 bytes
SHA-256: d9921c1241c5853635398a7b3efe93cc6a6e1484169030a3d6c9f76fa94a5f02
font_02_sfnt_off00012e7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1