Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f1ece8bf686003a…

MALICIOUS

PDF

89.5 KB Created: 2021-09-03 15:15:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 51f13583d90b387f4b5f519f9b15cc67 SHA-1: c1fa3d26a98f9465f90492254dd1d0c097861e0b SHA-256: 6f1ece8bf686003ab30d703005d7cebaa603d64fbf8fc2b135089eed5d605ea7
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites hosted on compromised or disposable domains, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The file's structure and link farm nature suggest it's intended to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://alshaabcoop.com/userfiles/file/96150611453.pdf In PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160de0ec2a8ba0---38476521183.pdfIn PDF document text
    • https://comfort8889.com/upload/files/35829568149.pdfIn PDF document text
    • http://dedanskecasinoer.dk/userfiles/file/11806539167.pdfIn PDF document text
    • http://www.aamuhsv-madisonalumni.org/files/files/5125432250.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/6k2gat93tkfb745h1iellhfeht/87238858094.pdfIn PDF document text
    • http://ned.ru/uploads/files/5162166422.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/sazizipovuroroxatasofuv.pdfIn PDF document text
    • http://aal.tw/uploads/htmlupload/files/36021121652.pdfIn PDF document text
    • http://foxdigi.com/userfiles/file/81479254855.pdfIn PDF document text
    • http://sunjewelsonline.com/userfiles/file/15322881799.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/160992ab533701---gazasifozikaw.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/53340022690.pdfIn PDF document text
    • http://gattoneva.pl/pages/userfiles/file/16943313667.pdfIn PDF document text
    • http://weilandensemble.nl/ckfinder/userfiles/files/49949907123.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/97107845215.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bc80a9ae8c2---68917171514.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/82323378932.pdfIn PDF document text
    • http://mudrkanuch.sk/editor_uploads/system/files/13289421981.pdfIn PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/fexaradinusokujofi.pdfIn PDF document text
    • http://hutbephottaihaiphong24h.com/upload/files/95042242434.pdfIn PDF document text
    • http://fabtur.ru/upload/files/43425299738.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/nisavuxatuzi.pdfIn PDF document text
    • http://thewesternmist.com/userfiles/file/50502062620.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=doen%C3%A7as+transmitidas+pelo+mosquito+aedes+aegypti+pdfPDF 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_off0000ef4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010761.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10761 11400 bytes
SHA-256: ecddc1b077ed997b9e89544c5bf1c8259587f6da393233173e07097f32de7fba
font_02_sfnt_off000121bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121BC 20632 bytes
SHA-256: 88c68f6bc763cd316e71b402e60309d84cfd2b3b748da7834370cce33ada634d