Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba7451dec5e4c414…

MALICIOUS

PDF

69.0 KB Created: 2021-09-18 12:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 73c4f1d6acd5e5e585852edcbdc3b698 SHA-1: 92a131674d49641705e4ca2f10b678ad5f05a1d5 SHA-256: ba7451dec5e4c4144bc87c598b1a6daf4c9cf2582e4d3fb13fbf89d5868eddc8
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to potentially harmful content. The primary goal appears to be directing users to external sites for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://tomorrowhubs.com/upload/users/files/62907849596.pdf In PDF document text
    • https://www.smartfutureexpo.com/ckfinder/userfiles/files/25748173294.pdfIn PDF document text
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/99119566864.pdfIn PDF document text
    • http://theponghop.com/upload/files/54814471081.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/wuvuwijotuzomigijiva.pdfIn PDF document text
    • http://stringladies.cz/userfiles/zaxupalawifugepezimax.pdfIn PDF document text
    • http://telesson.net/_UploadFile/Images/file/19724840162.pdfIn PDF document text
    • http://tyextractor.com/d/files/7922592068.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/nelotekagazexavex.pdfIn PDF document text
    • http://vpsystem.com/files/fck/gigovapadas.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140a4b186fcf---tusunas.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1630688568.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161341e92c5ca3---nutedizonetirowajeri.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/5b4bf1ab56c773ac5fb107b8f83900f0/kagixexaxonunesomimip.pdfIn PDF document text
    • http://scales-center.com/shop/fck_file/file/wegasod.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/85889725839.pdfIn PDF document text
    • http://rowerowaszkola.pl/imgturysta/files/26972947141.pdfIn PDF document text
    • http://makrostal.pl/user_images/file/73705413521.pdfIn PDF document text
    • http://j1ent.com/userfiles/file/20210910004626.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135a3af472a3---nifudotinafone.pdfIn PDF document text
    • http://kazuma.ru/ckfinder/userfiles/files/jufofuvexofepunemuxi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=line+shape+texturePDF 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_off0000b270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB270 14936 bytes
SHA-256: 2731a0df47d6c454c3d11f1cdf075f10c496e8c1a49ef89d35d6322e61794ead
font_01_sfnt_off0000d7a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFBC 10344 bytes
SHA-256: a960aad8f1b812d4e8314c94383771844718e279b9e669df5c3400c523c204cd