Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c9155e924be6a0…

MALICIOUS

PDF

84.6 KB Created: 2021-09-12 03:32:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5d464354cc2e4b708d6d402f070ad204 SHA-1: c0e9ff39369b9eb6ea7f61cc11985545e5dedc51 SHA-256: 91c9155e924be6a06795d0c297f5ff3f1ef9f99d282c80cf53d0466b59e0c845
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of embedded URLs, many of which point to compromised or disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://zezoalza.com/ckupload/files/pezafabafomitifesajonebo.pdf In PDF document text
    • http://goldenbaycruisesagent.com/userfiles/file/pazujelelipujut.pdfIn PDF document text
    • https://ethnicminorities.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/tosuzolusun.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131a5d92fbe3---tevuxukupirerikix.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021090210361848.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/35593723971.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/679c8fbcf4f53afb9a6a7cb3a397c524/45946547400.pdfIn PDF document text
    • http://plenaseguroseprevidencia.com/fotosempresa/files/pezulavenutaxoligajenirun.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/poxaforituriro.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/67051461508.pdfIn PDF document text
    • http://yuli-china.ru/d/files/99749662676.pdfIn PDF document text
    • https://tonerihned.cz/userfiles/file/zoxawidodekanokowitat.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/files/golalivuvujapig.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/tuliravilemuta.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/ao1ol1d4oe49q00kbhfrji2th7/55508120746.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/84156138996.pdfIn PDF document text
    • http://vinczeandlaszlo.com/upload/munesedolixosutedaxutogi.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/87308559566.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/vezujobujetufipasozobetew.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327f640de23---nonururevara.pdfIn PDF document text
    • http://dcbestwings.com/uploads/files/6352826741.pdfIn PDF document text
    • http://quiltingacademy.info/fckeditor/userfiles/file/moperiwutikilitaxakud.pdfIn PDF document text
    • https://vas-vill.hu/userfiles/file/bawunabiwakikoravupitofu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=ako+preniest+kontakty+z+android+do+iphonePDF 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_off0000dddb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDB 20496 bytes
SHA-256: feb68446208e59c00a7de60c6f133c1f47443d437b0ddf49944fa91e7b6fc1a7
font_01_sfnt_off00011205.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11205 10688 bytes
SHA-256: 10a2b7bbd9664f6c03da96f9f997a4906cbaa85979e902489a4e9e1962853c89
font_02_sfnt_off00012a93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1