Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f5a97fc724bd1a7…

MALICIOUS

PDF

92.1 KB Created: 2021-09-18 06:32:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 78b777bd75ce079c96965e07be318f3e SHA-1: d3355312c3b71aa6a579feccefc8edf36c1de9ac SHA-256: 8f5a97fc724bd1a718dfba87fa5120dfff96626640762e619c53bdb78e54cea3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous embedded URLs, many pointing to disposable domains and employing UTM parameters, strongly suggests a phishing or link-farming attack pattern. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9776

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nomylo.ru/uplcv?utm_term=you+and+i+movie PDF link annotation
    • https://artlabjo.com/userfiles/file/21001697612.pdfIn PDF document text
    • https://pratham.one/file/seramakudugariresofaji.pdfIn PDF document text
    • https://dichvuhappyhouse.com/upload/files/pumifobokitiluvixobera.pdfIn PDF document text
    • http://j-club.eu/userfiles/file/buwuwugukaratazesupuzu.pdfIn PDF document text
    • http://vektor-bezpeki.com/userfiles/files/19146706262.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/55578027948.pdfIn PDF document text
    • https://100tmt.com/uploadimage/files/20210901122950.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/82374007194.pdfIn PDF document text
    • http://bioaec.com/userfiles/files/98509053115.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/zubevakativibapemova.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/jitadipito.pdfIn PDF document text
    • https://starfoil-mail.nl/uploads/wysiwyg/10941225623.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/16968531153.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/fagibupe.pdfIn PDF document text
    • http://affectif.ro/data/Image/file/38391680816.pdfIn PDF document text
    • http://ydyb.com/filespath/files/20210916185712.pdfIn PDF document text
    • http://ncfc.com.tr/ckfinder/userfiles/files/88792354282.pdfIn PDF document text
    • http://ddaengshop.com/ckupload/files/pilibefolerexipatikix.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/dirubigose.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f50ef1de99---79592415981.pdfIn PDF document text
    • http://synhbio.com/upload/files/rewiruzemarujusukoluj.pdfIn PDF document text
    • https://bipalisdemo.dashindonesia.com/userfiles/files/22383995812.pdfIn PDF document text
    • https://marjoyunlar.com/calisma2/files/uploads/majavorakopexagakolekik.pdfIn PDF document text
    • http://globalcentral.net/contentupload/fckeditorUploads/organization_/file/rikoradosilijenak.pdfIn PDF document text
    • http://worshipedia.mobi/sites/default/files/file/potuvejovonaleguzabavupoj.pdfIn PDF document text
    • http://abwlargo.com/uploads/files/69234250362.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_off0001075f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011f76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F76 10148 bytes
SHA-256: 91378e5d0b9fa95d16b22bf29233c76ff1d4cd445d5778b61f1183ce568a1bd9
font_02_sfnt_off00013610.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13610 17364 bytes
SHA-256: 50c73e87180b8623d4146900b9b586160cbd2f7c5ce151747e51d05a93613d8a