Malicious PDF — malware analysis report

Static analysis result for SHA-256 f438f3e76321dcc2…

MALICIOUS

PDF

96.4 KB Created: 2021-08-03 18:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: f693579e8d4b28bfabed078293d261eb SHA-1: 186e84ddc6d87189a557c7f10eb0717145f578b7 SHA-256: f438f3e76321dcc208c1558e0ad89044e1b534b1539097e3469c174678f1432f
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users. The presence of these links and the overall structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.christianhouseshare.com.au/ckfinder/userfiles/files/donitogara.pdf In PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/64161323058.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dae7d5c122---31497069312.pdfIn PDF document text
    • https://autotronics.vn/userfiles/file/72137658108.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/1607e6eddaaab4---dakatemegovujupofinek.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/5aa2b946de708a14b46adea7224f6c29/tegixorisisafomafivasor.pdfIn PDF document text
    • http://farmina.ru/uploads/files/bubawudokozufejesa.pdfIn PDF document text
    • http://freewest.at/danokataxemuto.pdfIn PDF document text
    • https://alpinashop.bg/files/21213178963.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/81973555138.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/6ku1m2sd5jdl5i4plqepknm7lc/99365381730.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210623_084314.pdfIn PDF document text
    • https://timjanen.se/anvandarbilder/53/files/51201173065.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/76660277820.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080bedb2245a---negikat.pdfIn PDF document text
    • https://decoveinvestment.com/userfiles/file/texun.pdfIn PDF document text
    • http://thephinhmienbac.com/upload/files/96373847155.pdfIn PDF document text
    • http://cnhhgj.com/upfiles/userfiles/file/76371513211.pdfIn PDF document text
    • https://xn--mgbaf4adbs1bd2i.net/upload/ckfinder/files/xetuvugizijakimabosi.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/86703678115.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba4653f95d---bojoruxexizosowewar.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/70946683699.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/9gfui5v65sggi31gt58r9lb4jh/wibuxirisuvivado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=monocot+and+dicot+stem+anatomyPDF 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_off00011743.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11743 17132 bytes
SHA-256: 63bbbe7a1438dba46fdd041f93eb31b0585e736d4cbfb6c29119f98c0089296c
font_01_sfnt_off0001434f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1434F 10492 bytes
SHA-256: 2b60c12b76889edbc12b69d73d274e08b079c6f7e653724fa273febafdc13278
font_02_sfnt_off00015b3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1