Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ffdfc8546a4b783…

MALICIOUS

PDF

81.8 KB Created: 2021-09-01 14:52:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3959e075af1a5cd64e5e825060a07a94 SHA-1: 4ff9a87ba7aee828a3f9aeb899caea6095d0e49d SHA-256: 8ffdfc8546a4b783b790771fd927e125f1e8d7cff703228d73d24fb55ee8f67c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to compromised websites, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting and pointing to compromised CMS uploads. No scripts were extracted, but the primary attack pattern is the redirection to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://philabc.ru/uplcv?utm_term=sex+after+narcissistic+abuse PDF link annotation
    • http://impex-italia.it/userfiles/files/bigimeni.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/08c3114bac3107e7722bfe16a7694643/besad.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/jusetevagevijexekega.pdfIn PDF document text
    • https://markapin.com/calisma2/files/uploads/varukifapomerusitopa.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c661a4c2f33---81098723047.pdfIn PDF document text
    • http://daoltrading.com/userData/board/file/11116859514.pdfIn PDF document text
    • http://gsmontaggi.it/userfiles/files/zufaxodid.pdfIn PDF document text
    • http://es-manzokudou.com/yamituki-n/uploads/files/85346317988.pdfIn PDF document text
    • http://aweibel.com/Photo/file/75332342177.pdfIn PDF document text
    • http://superfishinglewood.com/uploads/files/pifenurovirakeduwujapize.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/nifagerulip.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/29452862552.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/48745403446.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/cafa122f1e930bcd6707a241919e56a9/80551507148.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/68800607296.pdfIn PDF document text
    • https://jamisonfurnace.ca/userfiles/files/xixuzeb.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d304765c757---sabefax.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609667fde9fcf---vevafuvoxebirate.pdfIn PDF document text
    • https://dewalt-naradi.cz/media/upload/editor/file/pesedejapegixutegirizoxa.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb78c45a14---96671586203.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16072dfb4d53cb---39023549102.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_off0000da21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA21 10580 bytes
SHA-256: 56721ffc83157d1baa0670d6b5399a082599c1e96e280a7cf450bcded994b5a6
font_01_sfnt_off0000f272.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF272 18480 bytes
SHA-256: e4a80eb76b70e0bd5c576a5b1148d1a21c224b2d24fa124fddfaeb382eeaaf87
font_02_sfnt_off000121b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1