Malicious PDF — malware analysis report

Static analysis result for SHA-256 cff1775e6d368e01…

MALICIOUS

PDF

80.1 KB Created: 2021-09-11 23:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 3105692e92d74465e9375858089f74fe SHA-1: 74b3b0d52d29e204d7aa35aa9b9c35beb1fd5c43 SHA-256: cff1775e6d368e01cb2db4f1d8314f4240a6336f4ba690efe577d97d9d2bf1e6
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 various domains, many of which appear to be part of a link farm designed to obscure the ultimate destination. Several heuristics indicate these links are hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://inwebjor.ru/uplcv?utm_term=rope+hero+frog+ninja+apk PDF link annotation
    • http://wabasnb.com/files/fckeditor/file/1290547974613af404e39bf.pdfIn PDF document text
    • http://buyyoutubesubscribers.com/ci/userfiles/files/50315756992.pdfIn PDF document text
    • https://khachsan295doson.vn/namthuan/images/news/files/zoraxazovusagibager.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/bonud.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/jemiforafemizopufu.pdfIn PDF document text
    • http://lamardaegu.com/upfile/user/file/83305712141.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wimagurulupe.pdfIn PDF document text
    • https://democv.associasuite.com/imagenes/contenidos/files/vesojafinedomugu.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/zunisitar.pdfIn PDF document text
    • https://yensaovinastar.com/media/files/girujozoniwizosuwuzapega.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wemop.pdfIn PDF document text
    • https://get-insurance.in/ckfinder/userfiles/files/23539343769.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/161321f3035466---dozolesakov.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/161378aaf8b90e---wanawuwi.pdfIn PDF document text
    • http://flirtproducties.nl/ckfinder/userfiles/files/gepumixetodadawi.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/gizuwuxarubisi.pdfIn PDF document text
    • http://changwontour.kr/FileData/ckfinder/files/20210905_4840F181797A4E5A.pdfIn PDF document text
    • http://mptech.vn/ckfinder/userfiles/files/tulunopefiwurot.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1f5553b4e---pajidenitaju.pdfIn PDF document text
    • http://freestyler.cz/img/file/79472503736.pdfIn PDF document text
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/35957328887.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_off0000d71a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD71A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF2C 17104 bytes
SHA-256: 1098cc4eccc82461e57732498d85eb60ddaba82495a3e6f97b6dbd008c7c8e9e
font_02_sfnt_off00011b7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B7F 10592 bytes
SHA-256: 63be33ce04a1e5cf6b2c70b4851d91c891541895dbd01ce1c64ecabc361dcd0b