Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d1b00fcb687938…

MALICIOUS

PDF

81.9 KB Created: 2021-09-10 23:01:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f4f3cb0e237e204457a547f156007151 SHA-1: f4e12d507d69386fe240e145110cdc67d999d86b SHA-256: 55d1b00fcb6879381235b2c6f0c98c37b1e8ee6df027f0c3b44fd974ab083c03
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous links to other PDFs, a common tactic for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to lead users to malicious content, likely a phishing page or a further malware download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://autonoleggioassereto.com/file/rupogawovubekodab.pdf In PDF document text
    • http://rsport.eu/yonexshop/static/file/70697550811.pdfIn PDF document text
    • https://lmcmanager.com/ckfinder/userfiles/files/71757246164.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/dulaxo.pdfIn PDF document text
    • http://creaorganization.com/depo/sayfaresim/file/xakovusesunobiraf.pdfIn PDF document text
    • http://ngocminhcnc.com/demo_thietbimay_24_7/upload/files/fikowewuridejemu.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/nomuwoxinefobefor.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fce2130999---93673684971.pdfIn PDF document text
    • https://ceral.pl/ceral/pliki/file/40892393061.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/fexifaxusiz.pdfIn PDF document text
    • https://legend-chang.com/UserFiles/files/78446762278.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/wubajabi.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/88346929676.pdfIn PDF document text
    • http://ricoconsultingattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/92420657301.pdfIn PDF document text
    • https://stw-nowogard.pl/download/file/fudubapeleguvan.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/venukaxipujulapinafov.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/20899332366.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/46759706384.pdfIn PDF document text
    • http://galettedesrois.eu/userfiles/file/12528969347.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/47516904932.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/83585123506.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/vopemorizuje.pdfIn PDF document text
    • https://dodatkireklamowe.pl/web/uploads/files/87611883709.pdfIn PDF document text
    • http://riverhouse.at/pcms/content/file/kagetexemonat.pdfIn PDF document text
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/30359431751.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=wallpaper+bergerak+android+gratisPDF link annotation
    • 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_off0000de98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE98 10792 bytes
SHA-256: 0303c5e25f0d5718cc31bc73d4cd32b388daf0676ec7c0eeb51dfa00edaa0c70
font_01_sfnt_off0000f71f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71F 16344 bytes
SHA-256: 1e51afab74566ccbd5d579158f0f3fedcf2057ac318de3340ec53abfd72e23d9
font_02_sfnt_off00012174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12174 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1