Malicious PDF — malware analysis report

Static analysis result for SHA-256 87738063a0a5b401…

MALICIOUS

PDF

97.9 KB Created: 2021-09-06 18:37:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 091932080eb9d7c2e8209715d1483f88 SHA-1: 1f00333b8b49e127041dc0d844388f49b452b2e7 SHA-256: 87738063a0a5b401977a0a046dc02a18f2e3cfce0cd87436dc2a56dfdc6cbdfd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, hosting numerous URLs that point to compromised CMS uploads or disposable hosting, likely serving as a distribution point for phishing or malware. While no scripts were directly extracted, the nature of the embedded URLs suggests a redirection mechanism, potentially leveraging embedded JavaScript within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16090528693794---3960850606.pdf In PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/48fd6f9aad7f8552242ea7d2164a402e/sasesu.pdfIn PDF document text
    • http://zezoalza.com/ckupload/files/67129019305.pdfIn PDF document text
    • http://abpaluso.com/upload/file/gafunazegozu.pdfIn PDF document text
    • http://jucal.es/images/file/rozat.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///34858214380.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e68ab0db195---6785491234.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b7ee24136e---47359942828.pdfIn PDF document text
    • http://elm3rad.com/file/91568506065.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/sibebevelodepu.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/n20cmjivrchodq1f512e3vk9ko/pamajoj.pdfIn PDF document text
    • https://srmresidences.com/images/bulk_images/files/vagesizidibogiw.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/758374cec1d4c045596a949de4e04ba0/dixudajerejem.pdfIn PDF document text
    • http://euro-ex.net/images/blog//file/gadukozavepote.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160aee5f39c457---70969374144.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160869759a0e86---mewajipopatawikemeb.pdfIn PDF document text
    • http://www.rannatennis.ee/data/upfiles/files/5007417770.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a6ba5dbba80ad438e194ea34f2c817b9/nozapoleresapokowibe.pdfIn PDF document text
    • http://actybrain-consult.com/Upload/files/58921335253.pdfIn PDF document text
    • http://izdepskifamily.com/clients/1/1a/1adacdf247316bc4617b3617d965acc7/File/52488737867.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a32b704b119---40180865667.pdfIn PDF document text
    • http://payassistinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160703909b1790---72418185569.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/14065804001.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c3daad4c3---49655786851.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/e89595pmch5ki2est81ljpg2fu/81099197470.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=measurement+uncertainty+and+probability+pdfPDF 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_off00011081.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11081 20988 bytes
SHA-256: 8852095ca4a8fc5e615a2ce80b1b93e6df49524596aeb6ebdbf50fc6c83627c7
font_01_sfnt_off000147b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015fcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FCD 11128 bytes
SHA-256: c8e8066abd10527cf469a3295f37dc209d9f8842e64e7652ffa729824ebf7a23