Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff22d25469722031…

MALICIOUS

PDF

83.8 KB Created: 2021-09-16 16:45:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 895103cb3f08aac8ec97e180caa18670 SHA-1: bdf62c20fc3c904b541b4d32bf8141356437b765 SHA-256: ff22d25469722031677a51de6d06973d8767ffc709813b9ab0eead4d0101f345
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised or disposable hosting domains, suggesting a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://chochosanencino.com/uploads/files/87355968882.pdf In PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109030814158354.pdfIn PDF document text
    • http://z500.si/files/79507687106.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210910_095042.pdfIn PDF document text
    • http://tacchigroup.com/public/thread/risorse/file/nufixemaviloposimadivut.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/movefuga.pdfIn PDF document text
    • http://qapoll.com/2015/vat/upload/files/48594625242.pdfIn PDF document text
    • http://associatedreclaimed.com/userfiles/files/wedinigibodixavexat.pdfIn PDF document text
    • http://doingthing.com/downloads/blog/geust/files/semunulasel.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/c7fa273d4c7bf83db66b698719b4a00a/94508699177.pdfIn PDF document text
    • http://av72-reklama.ru/userfiles/file/16314804430836a198b6174eecf02c.pdfIn PDF document text
    • https://lanhcongnghiepthinhphat.com/upload/files/latazajizobosikumose.pdfIn PDF document text
    • http://atol-res.pl/uploads/file/wajozedufafog.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/kufidibajukiruto.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16133d5e63bfe8---rivijowuv.pdfIn PDF document text
    • https://noticky.net/akce/fotky/file/fefiletibemebogeg.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f024064cb7---tolewunigubuwux.pdfIn PDF document text
    • http://idealthailand.com/file_media/file_image/file/kefebajerizefizelirigojo.pdfIn PDF document text
    • http://thepducphat.com/upload/files/46069133646.pdfIn PDF document text
    • https://ipssecurityconsultants.com/ckfinder/userfiles/files/diwanifox.pdfIn PDF document text
    • https://www.carnesvarejo.com.br/assets/ckfinder/core/connector/php/uploads/files/1238817307.pdfIn PDF document text
    • http://pensjonatagat.pl/userfiles/file/73474364464.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=windows+10+software+reporter+tool+high+cpuPDF 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_off0000e14a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE14A 17856 bytes
SHA-256: 282640b45694c19f05418b804e013f2756d1d8923e3143bebb950444d762f3f6
font_01_sfnt_off00010f15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F15 11252 bytes
SHA-256: df20e6ed5c39fc83891161dd9028c08dfcec6994da998fa3d7cb935e8d868360
font_02_sfnt_off0001294e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1294E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1