Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b11503b1fea3a59…

MALICIOUS

PDF

74.1 KB Created: 2021-09-20 12:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 27573ac279e6d450dbb5ec9bd71c0e15 SHA-1: b24cb0ff96324949c1c437476a1cd9fa60815494 SHA-256: 8b11503b1fea3a5945b2c8def93dcf123f3c1818f66508262f8a90b370266bf6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The presence of numerous external URIs and a heuristic identifying it as a 'link farm on disposable hosting' suggests the primary purpose is to redirect users to potentially malicious websites. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://irlanc.ru/uplcv?utm_term=8+pool+long+line PDF link annotation
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/901qe3vi38j8j45r6r0k8qsjv2/memapumigazemugokisa.pdfIn PDF document text
    • http://ls12368.com/userfiles/file/vuragujarotepunalejoguwet.pdfIn PDF document text
    • https://herfection.herfection.tw/upload/ckfinder_temp/files/20210908175714.pdfIn PDF document text
    • http://mylodge-naoshima.com/52093109910.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/56769442562.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210904041730.pdfIn PDF document text
    • http://chinalabware.es/d/files/21244113801.pdfIn PDF document text
    • http://srcchaika.ru/files/uploads/files/40966342059.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210914_115104_181.pdfIn PDF document text
    • https://anandalaya.in/resources/file/85802797316.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/tenesebupixunasavusu.pdfIn PDF document text
    • https://peusch.lu/userfiles/files/puguxopunixusut.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/de3s36bicssirhtididm53clr5/wowotolijabuvimazaj.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/nefojesezixelelil.pdfIn PDF document text
    • https://vinasimex.com/uploads/file/fabiwowegevoridupel.pdfIn PDF document text
    • http://baoveantam.org/upload/files/69363057817.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/kufidegizej.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/dasisatatemowe.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/wegebizagofat.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/nanufurozuvutaxodegazejin.pdfIn PDF document text
    • http://hongphuc.vn/userfiles/file/13221749851.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/60434276867.pdfIn PDF document text
    • http://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/tovefonikigukedud.pdfIn PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/45821070996.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_off0000c3b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC7 10012 bytes
SHA-256: 8e1ec8b3730509f60343440bfbf66336e2ae7321fb5391709b18e8374b719bcc
font_02_sfnt_off0000f1f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F9 16128 bytes
SHA-256: c2eb52fe38e93b9248f2ed46f9059532ef6672175cfbc8680f16d19bf26f2821