Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9cf712a3a9ee8a5…

MALICIOUS

PDF

87.4 KB Created: 2021-06-29 22:33:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 2e2c90cb829c66ad31d5e76fb38c528b SHA-1: c713fb9fe7367516653367115ed336123d774f69 SHA-256: b9cf712a3a9ee8a531af58f9de4213e4c163df5e748808b395de82c82814bbbf
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised websites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the presence of external links to potentially compromised CMS uploads and link farms is a strong indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://krisoc.ru/uplcv?utm_term=symptoms+of+gout+in+elbow PDF link annotation
    • http://koreaseowon.com/ckupload/files/dagogoditufivok.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/vc5doaqtaaqo3i404drfm0rns7/6884972173.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/laobcrtgg3dt0sjfddktvb1ia2/79765335885.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc6d81981d---bexituteb.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/36078210152.pdfIn PDF document text
    • http://playfromhome.org/clients/4/49/49939bf6a151252ba1adfe53d1befa29/File/bipiroxadevutexelevigatij.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/106d6c09ee24cca1cc707aa8f2d966bc/katufefejisowanorilabiles.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/76929700916.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c064bba9870---50679204943.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/n84ukm0l9tl1pcd2iblkib4hva/bovonigojobuzomufo.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160780ce6bf12c---muwupofuvigakeve.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/5ff426fc958b305b644f3eb433310c49/94363123381.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/17fc6aaabb19e7323b14fe3d368fc0dd/74164627285.pdfIn PDF document text
    • https://nbtele.com/en/cache/fck_files/file/9298436755.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccad9f08f6---jefirite.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/353730552a1053103a93fb71dc9c8528/5955556950.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607c55481ea4c---54718635279.pdfIn PDF document text
    • http://gloucesterclassof81.com/clients/23558/File/tugoxed.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3b9b23842---44014996334.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/202161895468161.pdfIn PDF document text
    • http://ipsgroupjjn.org/userfiles/file/ruxobemixamekosarura.pdfIn PDF document text
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7c4189901---82380984553.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/goxugaxuluguwalafafop.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/11393782942.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_off0000f02e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02E 17360 bytes
SHA-256: dc4d62b31ef3a1a33e82ea215e3dab80e11430f9ca8f2160ee04cb89ec2aff34
font_01_sfnt_off00011dd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000135f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135F0 10956 bytes
SHA-256: ef5da5fbf8103188ec9fd6bf0c67ca7375b2c293ca3d1c115e3f33897ff1cc86