Malicious PDF — malware analysis report

Static analysis result for SHA-256 4177a0ab322776d3…

MALICIOUS

PDF

82.3 KB Created: 2021-09-16 05:21:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 99c067e6ca1a2d5668bd36068e9269ab SHA-1: e1028987a65a325cb8c4e23d773992efc646a86c SHA-256: 4177a0ab322776d350844a704af6b10f65f729b6cea53f826ffeadb6eb92dc71
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics flagging it as a link farm on disposable hosting and containing algorithmically-generated URLs. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to redirect users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://drafthe.ru/uplcv?utm_term=is+an+android+box+legal PDF link annotation
    • http://yztools.com/images/upload/File/dulafemikoxotakanirapebon.pdfIn PDF document text
    • http://orkoien.com/userfiles/files/zewetamadisivawenobur.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zorumopusubemikekak.pdfIn PDF document text
    • http://moscowballet.ru/userfiles/file/32169979349.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/41202567778.pdfIn PDF document text
    • https://tatvan.in/userfiles/file/kalusojiwifobedofodenum.pdfIn PDF document text
    • http://inhome360.ru/admin/ckfinder/userfiles/files/50516068664.pdfIn PDF document text
    • https://praktijk-fix.nl/userfiles/image/file/buralu.pdfIn PDF document text
    • https://holcom-wd.com/webroot/img/files/funatosutefibakodum.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210910082503244.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/kinibakapuvid.pdfIn PDF document text
    • https://xuantruongtech.com/images/ckeditor/files/riboguvizesavijubo.pdfIn PDF document text
    • https://papersacksfactory.ae/images/bulk_images/files/71238462188.pdfIn PDF document text
    • https://cauthinh.com/luutru/files/44506606280.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134e84267a38---pagilesu.pdfIn PDF document text
    • http://gwardiajuvenia.pl/zdjecia/fck/file/ledoxi.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/xubesuveledonuzeruloga.pdfIn PDF document text
    • http://ideatity.com/ckfinder/userfiles/files/98864410145.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/89462195221.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/79485009088.pdfIn PDF document text
    • https://ecowaytechnologies.com/ckfinder/userfiles/files/94206316117.pdfIn PDF document text
    • https://shellserva.nl/docs/Image/file/jukebefefup.pdfIn PDF document text
    • http://fuerst-architects.com/uploads/file/14372401878.pdfIn PDF document text
    • https://matfplayer.com/calisma2/files/uploads/malixis.pdfIn PDF document text
    • http://servicedental.it/userfiles/files/47949015532.pdfIn PDF document text
    • http://hrdiborice.cz/erucom1/files/files/pipejiwepexeviku.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_off0000dc34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f44b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44B 10516 bytes
SHA-256: 712ca38d358280c07827903740b7dddbc63e98f0ab279348695e9d26f899f951
font_02_sfnt_off00010c11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C11 18308 bytes
SHA-256: 1d1d40ab48fc6cecc0b43204ee1d4687c96c6524106b8c18278e6da2f0425d56