Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa61354df33fbdb3…

MALICIOUS

PDF

83.7 KB Created: 2021-10-12 18:36:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1390e6ac7263141cd1ed853295cd75c9 SHA-1: e16fe8725cdc3c78064fe65bdc9f9fdbdde4e838 SHA-256: fa61354df33fbdb395c3181f6c3076b35985ae293d2c4a498af9020fdfc17715
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm, a common tactic for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and the presence of external links suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zhizhencn.com/filespath/files/20210921200606.pdf In PDF document text
    • http://boschvietnam.vn/files/usersfiles/files/51944045303.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/zipavekorok.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/wepufonomobixumix.pdfIn PDF document text
    • https://dp-silver.com/userfiles/file/43979425184.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0a96c3d90---85876258165.pdfIn PDF document text
    • https://attack.lt/images/files/xafijukidewadixiwuk.pdfIn PDF document text
    • https://butchercurnow.com/img/shop/contents/ditejepifikuredebowopuzi.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109010615448778.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/61805864087.pdfIn PDF document text
    • http://zhuoxinlaw.com/userfiles/file/20210923063441_1125974094.pdfIn PDF document text
    • https://abicecream.ru/ckfinder/userfiles/files/xotowil.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/xisofodowebirapadotife.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/novakadoloroborif.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/60914124511.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/3331452685.pdfIn PDF document text
    • https://butchercurnow.com/img/shop/contents/pagaber.pdfIn PDF document text
    • http://vodnik48.ru/content/file/koroledovanokifeja.pdfIn PDF document text
    • http://sartor.ru/upload/files/ribufedoroge.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/jatimenekitelirajiki.pdfIn PDF document text
    • https://keongracun.org/contents/files/zazimowuvop.pdfIn PDF document text
    • http://infinity-c-t.com/userfiles/file/zesone.pdfIn PDF document text
    • http://ukonlinedirect.com/userfiles/files/kajiku.pdfIn PDF document text
    • http://massimobertoarchitetto.com/userfiles/files/fuwezejoleg.pdfIn PDF document text
    • http://rc-modeller.se/images/file///61983956412.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/RC0zOYPQW8A/uplcv?utm_term=wib+to+pdtPDF 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_off0000e3b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B9 9804 bytes
SHA-256: ba723c657c5bc0b89e1af88d08c6b013d852639f79d7f789f0238b5eda0886b1
font_01_sfnt_off0000f90b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF90B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001111d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1111D 18476 bytes
SHA-256: 3e11668c50a1709e64a3be9e833df22ad72506fb04781a2da17370a223065a9d