Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb37dc8ebb524e5d…

MALICIOUS

PDF

69.3 KB Created: 2021-09-27 03:12:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: e22829ea26808525a686ef5bcdbfd815 SHA-1: b3dee842df8714cf54d883e3eec3a65c8426d268 SHA-256: fb37dc8ebb524e5d4774fb775cab54a20002cba9f8ea3293cc8763d1b9f03c42
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm with numerous embedded URLs pointing to potentially malicious content. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically flags the document for containing many links on disposable hosting, suggesting a phishing or malware distribution attempt. While no scripts were directly extracted, the PDF structure and embedded links strongly indicate an intent to redirect users to external, untrusted sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nomylo.ru/uplcv?utm_term=free+fire+game+download+app PDF link annotation
    • http://xinyaoqiye.com/upload_fck/file/2021-9-21/20210921042233587142.pdfIn PDF document text
    • http://gulfcoastlist.com/userfiles/file/5447610796.pdfIn PDF document text
    • http://flirtproducties.nl/ckfinder/userfiles/files/23289114704.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/50948501474.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/buluja.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/15307964194.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/nekasirenuwuwij.pdfIn PDF document text
    • http://cisseo.net/userfiles/files/lanomobexor.pdfIn PDF document text
    • http://rooptex.com/uploads/sibetutepoleguzofijewaji.pdfIn PDF document text
    • http://wizclub.net/upload/userfiles/file/13067155037.pdfIn PDF document text
    • https://holyfamilyhospitals.com/ckfinder/userfiles/files/xuxusopekipas.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090800040171333.pdfIn PDF document text
    • http://lemma-studio.pl/userfiles/file/loguguwuxowijaluleber.pdfIn PDF document text
    • http://nyett.hk/uploads/news/files/94361467153.pdfIn PDF document text
    • http://fotofolliasanlazzaro.it/userfiles/files/83816508803.pdfIn PDF document text
    • http://olympusflights.com/files/files/49742036196.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/31274475739.pdfIn PDF document text
    • http://magic-mugs-factory.com/uploadfile/files/90102358040.pdfIn PDF document text
    • http://4els.ru/uploads/images/files/29879069034.pdfIn PDF document text
    • https://mkserwis.pl/userfiles/file/ketekupamefomapajotov.pdfIn PDF document text
    • http://gibisch.org/files/files/xokizeronos.pdfIn PDF document text
    • https://mai-avto.ru/upload_files/file/91756076548.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/files/13410558101.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16148de4c62195---gulasibegusogatixuwevemar.pdfIn PDF document text
    • http://abogadosaguilar.com/ckfinder/userfiles/files/29194340957.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/e31f7741fba38554810bd48f6da264f4/38276226008.pdfIn PDF document text
    • 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_off0000b16b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB16B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC982 10640 bytes
SHA-256: c637741f449e53779b2581e54014a568728471b49dbd48c943f95b4e5f094c7d
font_02_sfnt_off0000e192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE192 15064 bytes
SHA-256: 5c8289b98b7998259e8797824aea1f9b65abf13c51bf8d4051c62d9c143ba4be