Malicious PDF — malware analysis report

Static analysis result for SHA-256 f77bc34a1812efc2…

MALICIOUS

PDF

80.0 KB Created: 2021-09-04 22:09:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 42bcb86546c4f54bf9c3598ead091b81 SHA-1: c74e79adf9c75bcaf24cfb45d877c30d6673b55c SHA-256: f77bc34a1812efc2b3e4ca37d6c213c2dbc56ab526e9f779024243366a1919a5
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests it's designed to redirect users to potentially harmful content or facilitate further exploitation. No scripts were extracted, but the overall pattern is consistent with a malicious document used for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://duhocblueocean.vn/ckfinder/userfiles/files/wovoba.pdf In PDF document text
    • https://mujeresenmovimientoplus.com/userfiles/file/pafitup.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d33b20d3281---21526847408.pdfIn PDF document text
    • https://kaisar168.com/contents//files/pobotigejemesaxiborawupim.pdfIn PDF document text
    • https://matratva.in/userfiles/file/73581645476.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fa4dbe104d---burugevijaj.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ab4bc067b55---sajisagatimanigexa.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba54898df92---34115034374.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/fuponifudasemisixexu.pdfIn PDF document text
    • http://dade666.com/userfiles/202108file/2021080114325270554.pdfIn PDF document text
    • https://samowar.me/userfiles/files/99493440432.pdfIn PDF document text
    • https://restaurant-kamkok.fr/img/Data/file/47529130156.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/99940956871.pdfIn PDF document text
    • https://101doctor.com/uploads/ckfiles/files/60b1c92311645.pdfIn PDF document text
    • http://artside.org/data/temp/file/nunugetupareriluxobagisag.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/4b62c56a8301484263c3900357d5f80e/pupobidiwimivuja.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/tijido.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/kepilazixoxizejiwusabefow.pdfIn PDF document text
    • http://nesthomes.in/userfiles/file/58869373492.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/67221383494.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/ralosutobejidev.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/39984106147.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=nutcracker+story+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_off0000d30a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD30A 10656 bytes
SHA-256: 03b1f6648924d9d531576718c67528f6c95ebb38913f3deb33a9bead87748b97
font_01_sfnt_off0000ebb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000103c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C5 18244 bytes
SHA-256: ae390f7efbfc978502ca5783b563fbb7b20455454984164a60f8edea4869b46d