Malicious PDF — malware analysis report

Static analysis result for SHA-256 a76e7357ca23dff8…

MALICIOUS

PDF

83.7 KB Created: 2021-09-21 09:45:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: f318b9fb0a45464f1d1936a77654e748 SHA-1: 61782fa0744ea838d02e9c2661dd6fae52781563 SHA-256: a76e7357ca23dff8998094bda756bee709744875d9620ef50a2ec4f477dab29a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm pointing to compromised CMS uploads. The embedded URLs and the PDF structure suggest an attempt to redirect users to potentially malicious sites. No scripts were extracted, but the PDF's nature and the heuristic firings strongly indicate a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://oniceh.ru/uplcv?utm_term=how+to+fix+sms+not+sending+android PDF link annotation
    • http://maquinandoysubastando.com/dleyes/admin/fotos/file/zatepimetofomovete.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/66511878227.pdfIn PDF document text
    • http://albertf.madteam.net/ckfinder/userfiles/files/disamolijunefifemoxumaxe.pdfIn PDF document text
    • https://photopoligrafic.ru/ckfinder/userfiles/files/neruraxuwebodibulo.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc73878da0---39503257363.pdfIn PDF document text
    • https://frigosztufi.ro/ckfinder/userfiles/files/4334059845.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16141f90b729ff---pidixufe.pdfIn PDF document text
    • http://alacartedesign.de/userfiles/file/66227278990.pdfIn PDF document text
    • http://giasudaihocsupham.com/Images_upload/files/98139839104.pdfIn PDF document text
    • https://gjbuyerbroker.com/userfiles/file/rizirejomezarakelamof.pdfIn PDF document text
    • http://traiteurluc.com/userfiles/file/vizufegik.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210911_194906.pdfIn PDF document text
    • http://retailcop.ca/files/zidimewupeminul.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/88680402723.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/3853957332.pdfIn PDF document text
    • https://libertyrealestate.in/ckfinder/userfiles/files/wogexexenuvetujuxa.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///202191819316547.pdfIn PDF document text
    • http://poliinc.com/upload/files/zibekilodeloji.pdfIn PDF document text
    • http://musicpark-live.de/userfiles/file/551087889.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/17485043853.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613fce53e7072---rawetiniritixo.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/salikugakekef.pdfIn PDF document text
    • https://ciiinnovationsummit.com/ci/userfiles/files/gotelubusiposa.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_off0000df1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF736 10828 bytes
SHA-256: a80ea526c5d0aea1584046153f978e0a7e0394fd5facad5df568a3a3c19006b1
font_02_sfnt_off00010ff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF9 18804 bytes
SHA-256: 81c78c82ee09bfdaf468373669baed22192b036dccf290a5eb60650292deb2b7