Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f18cc0aff2dc03a…

MALICIOUS

PDF

73.9 KB Created: 2021-09-21 13:03:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: feb33c6e2d2399d09a86a94ed9e2f5ae SHA-1: 5562f0942f38cfc70fd9a1216a07b8343b002480 SHA-256: 3f18cc0aff2dc03a51f630cb68805e36d9a8ac7a176e3c69ffc3e20600a711f1
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features numerous links to algorithmically generated URLs hosted on disposable domains, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://aluvioneschicamocha.sinecsas.com/ckfinder/userfiles/files/xuxozurexikajugime.pdf In PDF document text
    • https://openkomm.yussfone-crm.com/userfiles/file/pefegisakala.pdfIn PDF document text
    • http://446888.top/userfiles/file/lofulunoluberujejegilepu.pdfIn PDF document text
    • http://www.dagmarsvendova.cz/admin/js/ckfinder/userfiles/files/fedevizo.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/c02d54c64d8a89dd961d9705754c26bf/59353705563.pdfIn PDF document text
    • https://fullgame.hu/uploads/files/kinifeg.pdfIn PDF document text
    • https://sardiniagreencoast.com/userfiles/file/69690662355.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/buzigazifiwanisimab.pdfIn PDF document text
    • http://baovethanglongmb.com/upload/files/53299887275.pdfIn PDF document text
    • http://grandfiltr.com/files/file/11775648630.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/liwixosabotef.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/61522525250.pdfIn PDF document text
    • https://khabul.mn/mmpa/userfiles/files/legonifor.pdfIn PDF document text
    • http://china-guolin.com/filespath/files/20210902021337.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/moteloz.pdfIn PDF document text
    • https://holcom-wd.com/webroot/img/files/jifuwudila.pdfIn PDF document text
    • http://keletunderground.hu/images/uploaded_pics/file/36453470449.pdfIn PDF document text
    • http://denizyemek.com/images/fck_upload/file/95568549641.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/46277737538.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/77593889365.pdfIn PDF document text
    • http://khmim.com/ckfinder/userfiles/files/41128709671.pdfIn PDF document text
    • http://www.southpointinstitutehowrah.com/admin/uploads/file/xipobalokonevinor.pdfIn PDF document text
    • http://cascinamana.it/userfiles/file/67178732190.pdfIn PDF document text
    • http://uticachemical.com/files/upload/files/sidiniwibobomisem.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/vopisexilujodumojaxan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=fall+guys+free+online+gamesPDF 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_off0000bfea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFEA 10652 bytes
SHA-256: 5775c3a43ace7a7a2ae254cbbcd490112e3e476df5c066e280cbfd1726498562
font_01_sfnt_off0000d842.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD842 16400 bytes
SHA-256: ecc84e2d4654c64e79209ae2584784355c38007b74d884a6e17d4cfcb5e84c40
font_02_sfnt_off0001023e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1023E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1