Malicious PDF — malware analysis report

Static analysis result for SHA-256 4430e1c31865ec7c…

MALICIOUS

PDF

83.3 KB Created: 2021-09-17 13:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2b2969911070961734ba2b004d477640 SHA-1: 1044e65b345ad0d9ed8f3a51e976e9b9259f168f SHA-256: 4430e1c31865ec7cef7ba0b1aaa2fa86fc70e377e437f951b6bbea27e8c9b050
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on compromised or disposable domains, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple PDF-specific heuristics related to URI and link farms further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://infrive.ru/uplcv?utm_term=unit+test+android+tutorial PDF link annotation
    • https://esterkins.de/ckfinder/userfiles/files/53584504783.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/9f7d9e01aa4458f7ee28a6aa15d4de2c/sidijar.pdfIn PDF document text
    • https://homecareangels.ca/files/files/files/liluronote.pdfIn PDF document text
    • http://leadingedgecorporate.com/user_images/file/14391907035.pdfIn PDF document text
    • http://manchetenewsms.com.br/ckfinder/userfiles/files/42683052235.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/degoxudegeri.pdfIn PDF document text
    • http://hstechno.com/userData/ebizro_board/file/69562051437.pdfIn PDF document text
    • https://eniedu.com/data/file/20210917012510.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/14dad767fb774114ca5a9fdc41de2695/solowatukarujufedukil.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/9062363635.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d160ea0f71---gulofelosakesidimirofez.pdfIn PDF document text
    • https://bhopalliteraturefestival.com/mpsdp/uploads/files/99272375728.pdfIn PDF document text
    • http://tageedesign.com/ssmpt/documents/file/xisok.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/29012676940.pdfIn PDF document text
    • https://raovat72.vn/uploads/news_file/xibegowobibobonise.pdfIn PDF document text
    • http://elektrostroy.kz/ckfinder/userfiles/files/geladebobipafutejebezisow.pdfIn PDF document text
    • http://antasboru.com/guvennet/resimlerfiles/xumelofixibimojunuguk.pdfIn PDF document text
    • https://dakhoathienhoa.net/images/files/148643000.pdfIn PDF document text
    • https://bitree.com/ckfinder/userfiles/files/39892779752.pdfIn PDF document text
    • https://turbooto.vn/upload/files/17962945606.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161407fdc85592---gozasarazago.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_off0000e171.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE171 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f983.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF983 17708 bytes
SHA-256: e74dd0f91f79d25fdb364a861c162c6a141777194afb960e878b134a9ec62ded
font_02_sfnt_off000127e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127E9 10348 bytes
SHA-256: 16cec63434f40e2b3e2ad1bc49f167bfd94c49190670efe9f115794b46cfc318