Malicious PDF — malware analysis report

Static analysis result for SHA-256 a71c3c8ef59cb1f2…

MALICIOUS

PDF

88.8 KB Created: 2021-07-19 02:44:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 144cf54a105a344f04ec63f4b8aadf77 SHA-1: b8fac7482f97ff571b2bb5644a67e48a1e8686d8 SHA-256: a71c3c8ef59cb1f24e4568a66749637f3117a3c8eb8ee987cb73699abc7803a3
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which appear to be hosted on compromised CMS uploads or disposable domains. The ML classifier strongly indicated maliciousness, and the PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristic confirms the use of compromised hosting for distributing content. The embedded URLs suggest a link farm or redirection scheme, likely intended to manipulate search engine results or lead users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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://wintec-samu.hu/uploads/files/13427162575.pdf In PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607761b8c2499---dipufutivozir.pdfIn PDF document text
    • http://donleroy.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71791928307.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eef777df19---pudabi.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/vubovuborutitedon.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/15748872357.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/61841118723.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/9c7mn0ljtvu8de54o6lcpiqte0/jowid.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/68680758941.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab14c5f3782---79759388484.pdfIn PDF document text
    • https://kham.vn/userfiles/file/37675857855.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/cqtb69oi4fuvkhifged1n007ro/wirujazavuzowu.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160708df3cb8a1---75616102996.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/2u3nr4p95h2n6u8vr154qko018/5096053101.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/588b1824dd87711672c86e8c0b86f7f3/xofix.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/e2b8bde89c1ee599f01bc1bf987f74a6/23821175369.pdfIn PDF document text
    • http://fotossc.pl/_files/file/dudejizemelizivev.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210510010239.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/62836857536.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ecb2d11a0---jusizokafegekufuviriw.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4625818b53---fojofi.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/20751728980.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b1f682406---pudulubot.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/savukaxinetokonutumefij.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a3dde292b2d---3141165024.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=mystery+grid+drawing+printable+freePDF 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_off0000f76f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF76F 16824 bytes
SHA-256: 5c3bcc010e98e90531ef27bc8674b26b86e0973426c2df4832778c2cff5dc282
font_01_sfnt_off0001230c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1230C 10888 bytes
SHA-256: 1fede508b526749bf6b372bedb125bbe4ec21f056e93f2f50014b1470ced9bf0
font_02_sfnt_off00013bf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1