Malicious PDF — malware analysis report

Static analysis result for SHA-256 1185e47cf73b0de6…

MALICIOUS

PDF

74.6 KB Created: 2021-09-14 23:50:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 28e5b37794b8ba4a510239c7ef902bfb SHA-1: dbd1446539ecc0b04b30fc046f0a3ab200ac410a SHA-256: 1185e47cf73b0de6bf31fe9c9c1c1d1b82922620de21ea966c761868907acadb
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 ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure itself facilitates redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://krisoc.ru/uplcv?utm_term=clone+high+free+episodes PDF link annotation
    • http://llux.vn/uploads/files/5803124502.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/4282601556.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/4328300605.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/37215309915.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/24520841058.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210910101121.pdfIn PDF document text
    • http://locthanhwindow.com/img_duhoc/files/gamofejupoxebovivuwa.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/b71ada3da1603b31353c68326cb8f389/74816331474.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/33459974018.pdfIn PDF document text
    • http://rosniyom.com/userfiles/files/40954600517.pdfIn PDF document text
    • https://mkontroll.hu/File/livixegaxekabiboki.pdfIn PDF document text
    • https://mk-sito.it/uploads/file/1096208838.pdfIn PDF document text
    • http://abwbaltimore.com/uploads/files/49450799746.pdfIn PDF document text
    • https://shidoremicrosys.com/media/welutafek.pdfIn PDF document text
    • https://yensaovinastar.com/media/files/melasamirodiji.pdfIn PDF document text
    • http://achilleferolla.it/userfiles/files/lekijova.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/merodog.pdfIn PDF document text
    • http://sichera.eu/userfiles/files/71631924504.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/jujujavozidojisitakudijik.pdfIn PDF document text
    • http://onlineticketreview.com/images/file/91316157665.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16138a70507fee---venigobazokupofififap.pdfIn PDF document text
    • https://thailonghoang.vn/upload/files/58853854765.pdfIn PDF document text
    • https://sikanderajam.com/Robinson/ckfinder/userfiles/files/12110430464.pdfIn PDF document text
    • http://saveondealz.com/ckeditor/ckfinder/core/connector/php/uploads/files/vatiwufol.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210909201514.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_off0000c03f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC03F 10548 bytes
SHA-256: e9b5d807f7be956fcc0d17714fe05363743eb6f586054cd61d84e54b71c5d227
font_01_sfnt_off0000d7f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F0 17320 bytes
SHA-256: 8d847f5cfd35d50f6543c7bcad15cfe58448b96f439db1dc9bf7c00c8d011484
font_02_sfnt_off000104e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1