Malicious PDF — malware analysis report

Static analysis result for SHA-256 61c793bcb09e0259…

MALICIOUS

PDF

79.7 KB Created: 2021-09-03 15:17:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3aa5acc7d4d3475683856f3c4f39edf5 SHA-1: 1a8a529e02cc250f626e181791dfa6c2f466fdbb SHA-256: 61c793bcb09e02598c5189907ad7ab7fd9bafc8a1eb5df2bc24f8df2b181bb19
104 Risk Score

Malware Insights

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

The PDF file was flagged by an ML classifier as malicious. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various domains, some of which are hosted on compromised CMS platforms. The 'SE_INVOICE_LURE' heuristic suggests a potential pretext for user interaction, making it likely that the links are intended to lead users to phishing pages or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://gabortech.com/admin/file/lirolakag.pdf In PDF document text
    • http://linhkienhunganh.vn/luutru/files/jodabe.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/toxer.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/41bcdb12372e29bb19296323c4e11815/46641305050.pdfIn PDF document text
    • http://bahattinburyan.com/userfiles/file/vufalajijadij.pdfIn PDF document text
    • https://alutat.com/data/file/dowewigibiporekusuj.pdfIn PDF document text
    • http://www.jysunshine-hotel.com/up_files/file/xizemorisafamiselumaxukij.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/6ovbk2alcnk4aj3c4qjboah5rv/zonadegigifimeliluxafinux.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/49883637517.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1611edd1247569---nukefimobosuba.pdfIn PDF document text
    • http://gyobel.it/public/file/30631823576.pdfIn PDF document text
    • https://satuldelut.ro/ckfinder/userfiles/files/8962543228.pdfIn PDF document text
    • http://elsekmont.eu/userfiles/file/36916262981.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e516fb9b2a---4572533838.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160965a67ad77a---dijumofitezikudawe.pdfIn PDF document text
    • http://cafehinglung.com/uploads/files/musexinunusetegetiwivof.pdfIn PDF document text
    • http://vo23.ru/upload/file/7975525170.pdfIn PDF document text
    • http://inncredel.com/uploads/46343260129.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/f2d73ac14e738e2b930b50f6ee4d2803/sofuruxobuwetike.pdfIn PDF document text
    • http://samsung-service-center.ru/uploads/files/13037014736.pdfIn PDF document text
    • https://posh.hr/files/5767069211.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/mh8rg90su6b4fqj4gvruf92apn/41358306830.pdfIn PDF document text
    • https://songiadahoaian.com/upload/ck/files/74678775905.pdfIn PDF document text
    • https://ikansambel.com/contents//files/25813446063.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=jumping+to+conclusions+worksheetPDF 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_off0000d330.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD330 17256 bytes
SHA-256: b3a2adc517b054129f21459a3df5a50563767cd80cd062c111fedd39debf1bdb
font_01_sfnt_off0000ff94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117AB 10928 bytes
SHA-256: efbec87515a220f120983d79a7887b336cbfe67d1de8d6c6398d8f065b5e9bb4