Malicious PDF — malware analysis report

Static analysis result for SHA-256 da1d95295ac89cd0…

MALICIOUS

PDF

97.7 KB Created: 2021-09-06 21:45:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 39c4337d514d0990245aa2e78c6ff0aa SHA-1: 0dcdf4c96016f94cef29acdd4ef05b29806b5c0f SHA-256: da1d95295ac89cd01cb67f863ff48cc1dd852d3eca794fb532c14907fd2e0bc6
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links to other PDF files, many hosted on compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and URL patterns suggest a malicious intent to manipulate search results or distribute further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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 http://fructusartis.com/i/File/26285550531.pdf In PDF document text
    • http://ilkyoukais.com/Images/Media/files/wipabo.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/dubop.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/4a506182cdd39181295f2da6fb7ae9b9/88593555356.pdfIn PDF document text
    • https://soechi.id/userfiles/file/86594260561.pdfIn PDF document text
    • https://noticky.net/akce/fotky/file/4219784257.pdfIn PDF document text
    • http://pasted-radio.de/web/files/zozezuseneropapubejawo.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aca5790bcab---bikuvaropanu.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/vikerevifodijovixul.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/kumavatiko.pdfIn PDF document text
    • http://nfc.soo.jp/file/89169828322.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/jufezawijigedaxeworisav.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/ef227638c02c2236d3185d011a4709a8/jixezobesesugigudagid.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/xazemitutefa.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/8eb3109f661bee46d32a5f63787c0552/93955800465.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d7587bcdea---pumumovutomiw.pdfIn PDF document text
    • http://yogathoitrang.com/quangbasanpham/app/webroot/upload/image/files/zaxomodatufep.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/dea8bf7a9b40399d25352ddf52b20006/57616731158.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/ngt5dkfc0cksknqv3oeq6ml74p/rekajufabewutuzusolikami.pdfIn PDF document text
    • https://www.elshandmadedesign.nl/ckfinder/userfiles/files/95211280192.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/jibokawototomune.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/20497114357.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076f9bc0e372---60485689273.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160885d71977f2---sosexudur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=dyslexia+worksheets+ks3PDF 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_off000115c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115C6 19800 bytes
SHA-256: a83b5f014fbcdb187f6c66a4c68924a4df1489bd43bfc3a4981a872658c2773b
font_01_sfnt_off000148d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148D6 10668 bytes
SHA-256: e1f50cf2f2bf22609e4818fde86a56becf3aee0ffe093a3b1ea81ac03654ca0e
font_02_sfnt_off00016190.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16190 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1