Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9e851f617d252c9…

MALICIOUS

PDF

94.8 KB Created: 2021-09-05 09:48:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 79f7433c048ad956e260aca18e4e7cc1 SHA-1: 00bd8f5bf8d76bdd5cbe3f0a42a74ab73461d6cd SHA-256: d9e851f617d252c9288b95962c8602728dd05d6351cf15b8d77b6795a3f9a7a7
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. It contains numerous URLs pointing to external PDF files, many hosted on compromised CMS uploads or disposable domains, suggesting an attempt to distribute further malicious content or engage in SEO poisoning. The presence of multiple distinct hosts and the use of UTM parameters in some URLs indicate a coordinated effort to spread links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

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://orem.mn/uploads/files/jeziwisosopinetira.pdf In PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/16093398f52764---lexupevojeriwilinikudum.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607cbd62b8f1d---xixiza.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/a5837f8bc673857646fa02b364439e81/sakonavujulad.pdfIn PDF document text
    • http://thevale.us/userimages/zinedi.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16089838c747cf---jutokusagojajulopozibila.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bfedcf08093---11958288696.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/dudomedadunomesutu.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/ac6abbb73619ca6a631f94fdba4e1b7a/94244147163.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbf78de7bc---zosuwogivepenuku.pdfIn PDF document text
    • http://kiszelyugyvediiroda.hu/docs/file/11935563332.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210820022757.pdfIn PDF document text
    • https://indirimlipin.com/calisma2/files/uploads/guzelujija.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/baxojakinuwi.pdfIn PDF document text
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/8ccfed14a7ee50093a55fbde4118aba4/fubelolupakalenixabes.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160965a124d5d4---gokakinido.pdfIn PDF document text
    • http://highlandhighclassof1962.com/clients/c/c3/c330a44b04b080977bf299ea430a317d/File/modiv.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e9809817b5c---sudelupunasew.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb6a2201fc---76761838226.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/9ifelm2lfr6jo30rq2qv9tvt81/69040215057.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/zirojekipisimi.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/efqee0ed8rt8j6ibpqhk1qsiso/sedonemusinukedibudafixad.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/3ea1db740698f67bc6234dad03c5e4a3/53776245253.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160c90384e73fb---kobutale.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bd281b959f9---rokejig.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612d0e5c384f8---7972484295.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=worksheet+mixtures+and+solutions+answer+key+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_off0001095f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1095F 11252 bytes
SHA-256: 57cfcab2424b311235f33f4fe82d1ee653f7433757df46748cc7ef837dd20b5d
font_01_sfnt_off000123ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013bc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BC0 18716 bytes
SHA-256: 13dfb3f184af0a03fac99a68a97f41e5ff1b72e9f3bfab12e4a544fd12045441