Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4dfc5bc054c34b1…

MALICIOUS

PDF

83.9 KB Created: 2021-07-01 19:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 5b67f67159fe286cb016870ef212bf4d SHA-1: db59327de5b0f0527de41f4b70c631138791c89f SHA-256: b4dfc5bc054c34b1b3b7f01061b0fa6f31881dc9d7509f0ffd5fb59516149e0a
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://raiporjai.com/piceditor/file/58177573738.pdf In PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ce7c4c1ec53---81803458669.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608b082a316a8---74288834157.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/9angsolnv8gem8ndq2cr0lm3pu/78515990399.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/dijivuxinuximorebino.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/4ln0f5m5sg87cho7142o9j8uf6/sakugalo.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/19439265270.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/878e77ed199e687abd25a92cb391554c/zujivanizamir.pdfIn PDF document text
    • https://parfumzone.ro/files/file/96664199746.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-4-30/20210430081702929386.pdfIn PDF document text
    • http://fittbike.hu/files/file/74055758656.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4c542b421a---32097796117.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a64fc6acf45---subelepasobe.pdfIn PDF document text
    • http://lg-palette.com/upload/files/guvufozilo.pdfIn PDF document text
    • https://hotelindigha.com/FCKeditor/file/zimopusapevimox.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/rutamapiwatizuvoten.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/pgcomeo9q0vohv2246l3239qr1/tuxanibobudude.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/fivireturukitixasude.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160a3e239bae2d---8585442193.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/46995772156.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//78737457504.pdfIn PDF document text
    • https://anthonygillant.com/userfiles/file/sexeji.pdfIn PDF document text
    • http://maynenkhiinverter.com/media/ftp/file/jarofivanifiwisuperur.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/1607d4db6daa25---98930224054.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c5d63357a---nizefagemadafulolexamesaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=process+control+and+engineeringPDF 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_off0000e873.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE873 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001008a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008A 10544 bytes
SHA-256: 9c95f41609ffc6adfcf1a58658605d191564191379549bd44441da06a38cef1a
font_02_sfnt_off00011870.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11870 16188 bytes
SHA-256: 892260a18e603d544f1976a00b1cb19372486e09a3f1609f95ca38f055ea77bb