Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f1678d2e538b26…

MALICIOUS

PDF

93.2 KB Created: 2021-07-16 13:44:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 83b55603ac79a5e3e97e16848bcc1d46 SHA-1: 9fd0da89eaa6d99757e76a01b80f41d8bcde793c SHA-256: 79f1678d2e538b2618c498375a4adc0369dccc81b761d711df12c9412be9b5b1
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of embedded URLs, many of which point to compromised WordPress sites and utilize UTM parameters, indicating a link farm designed for SEO manipulation or to serve malicious content. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted from this sample, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9558

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=negro+meaning+in+english PDF link annotation
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d65edf2a19---65621818782.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b630cd7c382---vegepenidatuf.pdfIn PDF document text
    • http://bisenzia.it/userfiles/files/gejajinaxewizumusev.pdfIn PDF document text
    • https://prosperitas.be/data/assets/file/83719046002.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac2aaab334---82380330015.pdfIn PDF document text
    • http://landmanenterprises.com/clients/6/66/660ad4be7ac834282af30b44844c6003/File/40208277907.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/42094506603.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/583d489fe4a94ceba7cf5cfbbe030514/94940327506.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/lefemukudebujuzaxodofep.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a67b8aa0b10---nirimivopikulomid.pdfIn PDF document text
    • http://digivideos.net/ckfinder/userfiles/files/29707909901.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/bavuwaduvukelokimive.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/sodapujupokawexirunefekid.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/28934141831.pdfIn PDF document text
    • http://thaihotelsale.com/FileData/ckfinder/files/20210625_30F4381EF3437E2E.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/42533355230.pdfIn PDF document text
    • http://hillandbrownfamily.com/clients/76964/File/35951261526.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1608ba769ecb96---40271366444.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/qkdr3ll2flm5nd527ofm4ujgm4/jujisa.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/fd7e83d2bf5e97810b66a2c6f9ff327f/88675190527.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1dea3821fd---42340902419.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/80471693832.pdfIn PDF document text
    • http://www.halpellet.hu/userfiles/files/16662649751.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/5c60d8fb91a8de998816a0d88050465f/98060187411.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/vagutezazaxovaxab.pdfIn PDF document text
    • http://cosmickino.ru/sadm_files/wiwapedeso.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dfe7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F4 2288 bytes
SHA-256: 38b5f0e017e0ee574eb260be1ffd75968e09e079d287af4b718290aa3978b2c3
font_02_sfnt_off0001021d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1021D 21788 bytes
SHA-256: bf7110073593989c47426d15b26873971a17e33a85028e85a01db595646cd673
font_03_sfnt_off00013798.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13798 10436 bytes
SHA-256: 71e452ccff95a5e82411a3a2a891d18722885b146452a3b9c57a1d5d8d068564
font_04_sfnt_off00014ef0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EF0 16572 bytes
SHA-256: a5b978592084bd7287b0f8ffa73d535b66f3e146885d7c5959e4278f2f1bb1b7