Malicious PDF — malware analysis report

Static analysis result for SHA-256 a004f8492b501614…

MALICIOUS

PDF

68.4 KB Created: 2021-09-29 00:09:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 53a3187c7c3611e177447a9e368abb85 SHA-1: be4fb339d1dabd8f8aa8af8948ef84816ee3b948 SHA-256: a004f8492b5016141888fe42515f61ba1388eacec59a667f973775750188be36
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as link farms. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicate a pattern of using these compromised sites to host or redirect to other malicious content, likely for SEO poisoning or phishing. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://ketchas.ru/uplcv?utm_term=minecraft+pe+apk+sum PDF link annotation
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/72c029eb7a63544ff899621661ccea9b/12215188340.pdfIn PDF document text
    • http://chhattisgarhsanskritboard.in/sharpinstitute/images/files/4697566457.pdfIn PDF document text
    • http://moiarchitekci.pl/pliki/file/88203654598.pdfIn PDF document text
    • http://mjacz.cz/soubory/files/laronefutikuputawezarakun.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615383eb86c69---lekodadisumibatu.pdfIn PDF document text
    • http://labsshop.com/d/files/nemulokadas.pdfIn PDF document text
    • http://bbfrontedelmare.com/userfiles/files/luvilarineloduxibenogir.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/64810069206.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/lubonojaxuzevofe.pdfIn PDF document text
    • http://gewald.ru/content/Files/97525783505.pdfIn PDF document text
    • https://lee-trading.tw/archive/upload/files/mojivenadopilositefo.pdfIn PDF document text
    • http://bytip.net/filespath/files/20210913045126.pdfIn PDF document text
    • http://knuhpharm.kr/userfiles/file/20210902140905.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/zidojakezidati.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/nu7s3pkd3v2ce9ng7vl3us5o72/80006444836.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/87268166473.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a922f41788---pipunutofanixil.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/11780612163.pdfIn PDF document text
    • http://marine-inox.com/i/File/47037227269.pdfIn PDF document text
    • https://peoplehelppeople.net/uploads/File/14498086241.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_off0000ab0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAB0A 10660 bytes
SHA-256: 1bdabe00d889b1b50ad6beb2fb66f18b728a83abc6e302a12d4ec950aba503f4
font_01_sfnt_off0000c37c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC37C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000db8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB8E 15988 bytes
SHA-256: dd286803dedb5abed6bebfdf2eb94e78ff9eaa3faa581e2c54ee90cf2ee6a0b6