Malicious PDF — malware analysis report

Static analysis result for SHA-256 3df1d7c56fe9ba4d…

MALICIOUS

PDF

117.6 KB Created: 2021-07-31 12:06:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: b6134e9aa388c597008420a6ad338cf1 SHA-1: e3e579b6bb05045230abc899d56058c45c1434b0 SHA-256: 3df1d7c56fe9ba4dd10b0bbf533a578b22ae24a73026bc625ea69a16084b655c
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains heuristics indicating it is a link farm, potentially hosted on compromised CMS uploads or disposable domains, and is flagged by a machine learning classifier as malicious. The presence of invoice and download button lures suggests a phishing or social engineering attempt to trick the user into downloading a payload. No scripts were extracted, but the overall structure and URL patterns are indicative of a downloader or phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://verynailscm.com/user_img/file/35940289695.pdf In PDF document text
    • http://duszek-lasu.pl/userfiles/file/7129223276.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/gasapitufonera.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/5fc73c6833e8a3afd3dfdddd72cc4ca2/47532077221.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/002ba426c43591dcf6a6e349f8610d0a/jexigezirof.pdfIn PDF document text
    • http://wccflooring.com/userfiles/files/5964921941.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/wapoxopibirunewo.pdfIn PDF document text
    • http://abwcrainhwy.com/uploads/files/26947773639.pdfIn PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/62624408200.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/44309384188.pdfIn PDF document text
    • http://billsky.ee/files/file/23029798989.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/b9881c4247f0c01d520a047c8e4411fd/lofavase.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b337181591c---26835930575.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/wefutimudolejufugo.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/pulupofev.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c71dc9f1811---kebuvifajedokibizefuwixe.pdfIn PDF document text
    • https://ooo-kenk.ru/userfiles/file/jutab.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e4a42982d22---kunabarasa.pdfIn PDF document text
    • https://healthcareadvisorsgroup.com/wp-content/plugins/super-forms/uploads/php/files/hqgnq5l035b5jelrmjlhhli036/45177966305.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ea9911539---velakawakisigixepe.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202107252142445876.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f68fbb8be3---22775817628.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/10903111775.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/ca78apg9krogrhnrmnq6nmfttj/33369194003.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+wrap+cord+with+stringPDF 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_off0001657f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1657F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00017d91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17D91 18992 bytes
SHA-256: 9168954b383c863921c0aff944d37ea9f3bfd88d8997ff5b67f51323e28370b9
font_02_sfnt_off0001af7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AF7B 10692 bytes
SHA-256: a8fdf3708a9d96b2ce36e5dc320333c8c510d1a267e1301e2d3235248e7317e3