Malicious PDF — malware analysis report

Static analysis result for SHA-256 85840db3b7fab7b2…

MALICIOUS

PDF

75.5 KB Created: 2021-09-24 05:45:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f818055fd7ced9475a7e5ed20bb4da6f SHA-1: bbc52d577f129d8d833d40c396160af3d2d8d261 SHA-256: 85840db3b7fab7b260d9703948300fecb6ada26aa0794f8261e3fe2da623cfb8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • 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.
  • 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://medvor.ru/uplcv?utm_term=black+widow+yts PDF link annotation
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a699878fc9---remogudegopirazutabora.pdfIn PDF document text
    • https://guijek.com/userfiles/file/76280296165.pdfIn PDF document text
    • http://hlqh.net/userfiles/file/20210903184327_746813679.pdfIn PDF document text
    • https://amityhr.com/userfiles/file/13984990584.pdfIn PDF document text
    • http://ehomeforeclosure.org/images/file/mubiwet.pdfIn PDF document text
    • https://dnm.tw/uploads/files/202109040728016798.pdfIn PDF document text
    • https://omnistopbollards.com/application/third_party/ckfinder/userfiles/files/fuvitijolenawipadawotevo.pdfIn PDF document text
    • http://sinners-party.de/media/file/lipenokaxovokivuva.pdfIn PDF document text
    • https://windscrm.net/files/file/ferivabexepedababalafi.pdfIn PDF document text
    • http://gibisch.org/files/files/32133678947.pdfIn PDF document text
    • https://digireg.org/upload/komexefudejifo.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/b9hc080f2ct3vu4auuvi2cgv5i/zovapalugulubebifukaxiz.pdfIn PDF document text
    • https://ladangmimpi.com/contents/files/20235612816.pdfIn PDF document text
    • http://cukrarnakolbaba.eu/obrazky/files/lotedugoma.pdfIn PDF document text
    • https://lrsdev.com/userfiles/file/namize.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/52539717569.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364d9f9aaa8---zariv.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/20301247531.pdfIn PDF document text
    • http://studiotecnicomancini.eu/userfiles/files/44032042139.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/paxabobabilutedirow.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/damupezikamebarig.pdfIn PDF document text
    • http://xn--80aaaaadfwa5aftjhxrkcrg8iwc.xn--p1ai/pict/file/95139657860.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_off0000c0f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0F9 10372 bytes
SHA-256: 05b0f293e56422d370fd66f575db369c536a7fc6f2c2d288a31abbe350553156
font_01_sfnt_off0000d8ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0BD 18092 bytes
SHA-256: 84d758c7b93cf5fa6b04d54eecc3ab0b58e2fa85a4ba9d40296b5297e193f641