Malicious PDF — malware analysis report

Static analysis result for SHA-256 8daf7930db1a2723…

MALICIOUS

PDF

76.1 KB Created: 2021-09-10 03:49:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 19f67544a44b58a885a772a38ef49524 SHA-1: 90c5fc2cc0c268756f4cbd940c72ddfe4db3332b SHA-256: 8daf7930db1a2723f9730ec1fb697d86404a6a51a5ecc66a2ac33051e6b0b58f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs, such as 'https://queure.ru/uplcv?utm_term=probability+and+statistics+schaum+series+pdf', are likely used to redirect users to phishing or malware-hosting sites. Although no scripts were explicitly extracted, the PDF structure and numerous external links suggest an attempt to exploit users through indirect means, possibly involving embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://queure.ru/uplcv?utm_term=probability+and+statistics+schaum+series+pdf PDF link annotation
    • https://eurosan.pl/user_images/file/gotawokopiviwixapibogi.pdfIn PDF document text
    • http://agedwedfjtj.pretty-match.com/upload/files/zotuzezosuxugasukor.pdfIn PDF document text
    • http://sabaparsian.com/ckeditor/files/files/47879772460.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/78511491977.pdfIn PDF document text
    • https://allora-tour.by/var/upload/file/remufifudojifidexatamub.pdfIn PDF document text
    • https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/jevuwudopusuxidifet.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/vabamapogirisukibo.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/lajokuk.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/3ecd35d88c685d06aa50c3f11f253a7c/fifiroxobebajaxa.pdfIn PDF document text
    • http://qzgj.cn/upload/file/mikobene.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/23362850715.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/81572802767.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/wosuwizonegugali.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/36494572783.pdfIn PDF document text
    • http://tajeer.co/userfiles/file/tawuxomokomotudufot.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135823b7904d---fejefuwadomikejarulefam.pdfIn PDF document text
    • http://9y.bfage.com/upload/files/20210908100301.pdfIn PDF document text
    • https://tsydesign.com/userfiles/jws/files/rodotuwatunuruwapitiref.pdfIn PDF document text
    • http://gimnazjum-krasiczyn.pl/img/userfiles/file/32085407255.pdfIn PDF document text
    • http://www.bandungmesin.com/file/59843616689.pdfIn PDF document text
    • https://cuichi177.com/uploads/files/202109070606471146.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210902175040_548161179.pdfIn PDF document text
    • http://sjhrz.com/images/upload/File/92817626980.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/66003411465.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_off0000c505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC505 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD17 16936 bytes
SHA-256: 5d648c2094e0557f0e070e4341d05d15845e5d2107593438e4aed7a2f2abcb0b
font_02_sfnt_off000108b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B2 11240 bytes
SHA-256: 821126851d2cc881510238ecb6ce49412254eb1c8f13f47407dd8e160b55c4a1