Malicious PDF — malware analysis report

Static analysis result for SHA-256 2ef1af0abcf8d795…

MALICIOUS

PDF

74.6 KB Created: 2021-09-12 13:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ce4f280bf7f6ddc9d7e99eb097db339d SHA-1: 50fe6127407d0bb939c011c3931e96d1ea3a82e6 SHA-256: 2ef1af0abcf8d795af617622c4ce5bcc60d768b7b75bd3421071d63413e3dbf0
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to other PDFs hosted on compromised websites or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to appear legitimate through link farming, while 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicates it leverages compromised content management systems.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://www.prshots.com/ckfinder/userfiles/files/nusogel.pdf In PDF document text
    • https://chsins.tw/uploads/files/202109041111572733.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/572da2756be8f28a53218dff73af392d/65321955612.pdfIn PDF document text
    • http://chothuethietbi.info/img/files/44018432909.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/65389338812.pdfIn PDF document text
    • http://open.ua/uploads/ckeditor/files/momamuxajisi.pdfIn PDF document text
    • https://florerialafloresta.com/ckfinder/userfiles/files/34557278142.pdfIn PDF document text
    • http://creaorganization.com/depo/sayfaresim/file/povuwonokol.pdfIn PDF document text
    • http://micdelhi.in/userfiles/file/79216532166.pdfIn PDF document text
    • http://udaybharat.in/ckfinder/userfiles/files/55712374718.pdfIn PDF document text
    • http://xn--80aikni6a0b.xn--p1ai/images/file/nezalurenekutivazer.pdfIn PDF document text
    • http://3mfa.com/images/editor/files/52703797893.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5fdec93a1---dexefuninusajatoxepotim.pdfIn PDF document text
    • http://vindindex.nl/images/uploads/pegum.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/minitovodugisenid.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/48256913250.pdfIn PDF document text
    • https://irepairplus.nl/app/webroot/files/userfiles/files/68349167950.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/1b0c42437c10e4386644a4c9c23207f9/90518025379.pdfIn PDF document text
    • https://efnnma.org/files/file/2263298694.pdfIn PDF document text
    • http://pphjako.pl/userfiles/file/jokonawanomesiwamafosifum.pdfIn PDF document text
    • https://media-get.com/userfiles/files/tugeg.pdfIn PDF document text
    • http://k2plusinterior.com/userfiles/82726122477.pdfIn PDF document text
    • http://mikailang.com/userfiles/file/20210912134819_1987081409.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=sayhi+mod+apk+2020PDF 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_off0000bf4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF4B 17716 bytes
SHA-256: 0af00e90afc838741909624d3654f2232cf99e36c496b56eb874e35bb312a5c2
font_01_sfnt_off0000ed66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001057d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057D 10532 bytes
SHA-256: 076343afd4a1a73fa833a18b70b1160ad340612e3f297d26fb5f948b7c45580d