Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad6f3fa0b3a9d2a0…

MALICIOUS

PDF

70.2 KB Created: 2021-09-21 20:13:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 847f69430ebd910225d176b2d6f27499 SHA-1: b3c7fc502cb19a0ef36b1934a94f28ebdde44a38 SHA-256: ad6f3fa0b3a9d2a0f1884a7a11818d689085fa643df86ee248ec5c85b8338c61
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files, many hosted on domains flagged as compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO abuse. While no scripts were directly extracted, the structure suggests a malicious link farm designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://gnox.vn/upload/files/dorapixikegirajewa.pdf In PDF document text
    • https://andhimazhai.com/images/files/vasalomegovukikukef.pdfIn PDF document text
    • http://www.humillacionyestrella.org/ckfinder/userfiles/files/xunirufupezi.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16147316d60fc1---74094803323.pdfIn PDF document text
    • http://karinameal.com/imgdish/files/52165697571.pdfIn PDF document text
    • https://efficientinfocomm.com/ckfinder/userfiles/files/12712108417.pdfIn PDF document text
    • http://helder-effect.nl/userfiles/file/45614867226.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/rurimanejuzu.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/71609900456.pdfIn PDF document text
    • http://wsmr.us/userfiles/file/dazutipevolipudef.pdfIn PDF document text
    • https://bangprice.com/bangprice.com/beta/cms_image/file/nevipevavaxodafik.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/zuporalelev.pdfIn PDF document text
    • https://webvitamin.vn/app/webroot/uploads/files/dejemisixoji.pdfIn PDF document text
    • http://allasclub.com/campannas/file/34186066621.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/malurab.pdfIn PDF document text
    • http://seychelles-resort.com/images/blog/file/linugow.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/rupifazuvujananuvek.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/39632084148.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/kqukcjj41mg0ck90p0sq4k00a0/gixavijuji.pdfIn PDF document text
    • https://eminencesolutions.in/resources/userfiles/file/5570428600.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/soxape.pdfIn PDF document text
    • http://jyy.jp/ckfinder/userfiles/files/20210921_045035.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/346f7b68de4e58d225997dd8f9c3ea67/biwiba.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/judavaputokoripujelexuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=thoptv+latest+apkPDF 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_off0000b497.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB497 15724 bytes
SHA-256: 9f4b4ec8da6fd6b94dcf3a8b0bec94538adff0f098fc5f1c645587d546463d3d
font_01_sfnt_off0000dc99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B0 10172 bytes
SHA-256: 6017d4e6356320326f64302bbf3fade98aabfe6784bcb41bd86ea0dd62d9f990