Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6f528e1cefed297…

MALICIOUS

PDF

90.4 KB Created: 2021-07-18 03:29:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7716f737cee5df684146ab3ba3d01ccc SHA-1: 3432b59cf1f595d03e0e96c286d22b8fa59dbfad SHA-256: f6f528e1cefed297e402e99c5193eb4ff5a152119007ac70edd29ade20f643d8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm that points to multiple websites, many of which appear to be compromised CMS uploads or hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to phish or redirect users to malicious content. The primary attack pattern involves luring users through a malicious attachment to a network of redirectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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 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 https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/tuh47girqjdk36hm0or8etucsc/29706497551.pdf In PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/02179e7a20a22065f30a4fa3efd1c38f/97739111283.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a74f7b079---42900060950.pdfIn PDF document text
    • http://cameranichietsu.com/luutru/files/75606588864.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608602d76b601---48114983450.pdfIn PDF document text
    • https://thefertilizerproductionline.com/d/files/rupasobilisubenaxoxeg.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607196a038904---ruwupa.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c240c6b22be---3357422942.pdfIn PDF document text
    • http://aexpress.lv/index/images/up/file/9652532879.pdfIn PDF document text
    • https://whiteelephant.co.in/wp-content/plugins/super-forms/uploads/php/files/2935d14673cb6c6b6220e3012cb00b0a/23455279938.pdfIn PDF document text
    • https://bhandarisurgical.com/ckfinder/userfiles/files/19854905208.pdfIn PDF document text
    • https://teenvolunteerhouston.org/wp-content/plugins/super-forms/uploads/php/files/ab26f49f14916eba3e2decec806735b4/87345656935.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607796b470808---25427645068.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/pafup.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/708a4b8e4a78ba9215e5ef801cd138c1/24713347081.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a270663e4ca---finurepivufo.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16078439fe1878---masagobejigutepax.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/160ace9181ce69---xekebadufavoki.pdfIn PDF document text
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dbe44d4ab8---6715708975.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/c778c556bac2175e1e11980479e7da39/62752302996.pdfIn PDF document text
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/f4098ac1c0fb63be393972e5c5838da1/xikajadakudikafutagi.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0d2eabe34---1123878415.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/wakajekotir.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087ad341cf62---40887915685.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/buwuxowinowaz.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075a8395f555---pojakomivakuripopulitada.pdfIn PDF document text
    • https://bloc-immo.com/images/luduvigogibazeziduno.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=atheistic+materialism+meaningPDF 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_off0000fdd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD0 10536 bytes
SHA-256: e3660e289fdcd4e6d00c4951fdc5ce8395164fdf879a3531a076fed83d6b3133
font_01_sfnt_off000115a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012db8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB8 18308 bytes
SHA-256: 06f4a2b5942adeaa73aa8722c99eb2fc4c62a6288199d911848fa0b54ac5bd96