Malicious PDF — malware analysis report

Static analysis result for SHA-256 81cd6b760639799c…

MALICIOUS

PDF

82.3 KB Created: 2021-08-19 22:52:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: d7f4a002adecb924b8df5a8f0441d31a SHA-1: 736b9131598d2bb9a93270c81dee577726b30b77 SHA-256: 81cd6b760639799c9a1e51a09d57b2db160d1222d2da28f6aa5b8a976e7230c4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV as a phishing trojan. It contains an embedded JavaScript stream and numerous URLs pointing to compromised WordPress sites, forming a link farm. These links likely serve as redirects to malicious or phishing content, indicating a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b11e38cc520---lejuwaposimevapu.pdf In PDF document text
    • http://anatolianlgs.com/userfiles/file/73230305549.pdfIn PDF document text
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/vovavanumovupek.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/n51c2fehud5f6bdjujvqqrm8c1/54995614483.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a21f6c6caba---9003649759.pdfIn PDF document text
    • https://norservis.info/files/files/80322331999.pdfIn PDF document text
    • https://rugerwafers.com/demo/ruger/beta/userfiles/files/xunuliziza.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607242ee0a9b3---duvalimaseremuwusage.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/2a742de490284ed3a70bd61e4669fc87/42578990970.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/27040024460.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/zifofivaxagim.pdfIn PDF document text
    • https://nepalipublisher.com/ckfinder/userfiles/files/pokeparapuzuraxome.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/12986285611.pdfIn PDF document text
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/45057298670.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd50e820762---bujuje.pdfIn PDF document text
    • http://grandrosso.com/js/upload/files/31937062005.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b0227c90b5b---naxozuvukipolodimepedotif.pdfIn PDF document text
    • https://curewelldiabetes.com/userfiles/file/vemesizegepisifataseb.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608c67b84aed2---15588915831.pdfIn PDF document text
    • https://rosycaffe.com/file/49648193523.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/97385771460.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/fdfca1df37dfc8d2805e19d8772594a4/58761925168.pdfIn PDF document text
    • http://architettipassarinmarzotto.com/userfiles/files/20367270146.pdfIn PDF document text
    • http://wangyiphk.com/userfiles/24856839875.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=12vdc+to+12vac+inverter+circuit+diagramPDF 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_off0000dd04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD04 16796 bytes
SHA-256: daab2bd20411192d086df70311fce0d20e7d1020a88f84e78cc097a77e823e1e
font_01_sfnt_off000108d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120ED 10740 bytes
SHA-256: 5dec163dfdec5526047ee72708a151043de10f78cb5bf0f4887235fd83774e5f