Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a43b8ee67b32f5…

MALICIOUS

PDF

69.7 KB Created: 2021-09-28 18:53:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 55af1e7ebd8f6f85719aec559d08038b SHA-1: 2bea371b32b9c24d9dba2754ef073b7ae2bd4d9f SHA-256: b4a43b8ee67b32f5702ec4ac26375b203e92bb9e5930cf0a736dbce3fcfc084d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and numerous external URIs. The presence of embedded JavaScript (T1059.007) suggests an attempt to execute malicious code or redirect the user. The numerous external links, some on disposable hosting, point towards a phishing or link-farming scheme, likely delivered as a spearphishing attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://catamma.ru/uplcv?utm_term=super+tank+rumble+mod+apk PDF link annotation
    • http://atomicattack.com/atomic/fckimages/file/47101005102.pdfIn PDF document text
    • https://nhomphuongnam.com/upload/files/balosowuwunawab.pdfIn PDF document text
    • http://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/17502941107.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/demulemajasese.pdfIn PDF document text
    • http://montaze.org/democms/userfiles/file/jixizaguzepuporepireda.pdfIn PDF document text
    • http://123flower.doweb.kr/upload/files/kajefekowozuxuved.pdfIn PDF document text
    • https://jaurrieta.net/USERFILES_JAURRIETA/files/refagazeraritudesi.pdfIn PDF document text
    • https://ebooksweb.net/files/file/tumexoninifep.pdfIn PDF document text
    • http://gursakaryahukuk.com/images/file/2401826221.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109081838087759.pdfIn PDF document text
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles/files/zelusot.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16130250f99b31---76290607402.pdfIn PDF document text
    • http://koslita.eu/ckfinder/userfiles/files/23475224832.pdfIn PDF document text
    • http://stapper.de/sites/default/files/userfilesfile/4336247370.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/40170064587.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/1266995437614b1c27afb18.pdfIn PDF document text
    • https://newtech-utm.pl/userfiles/file/59732081436.pdfIn PDF document text
    • https://www.l-games.jp/js/ckfinder/userfiles/files/vuwetekisabamugonu.pdfIn PDF document text
    • http://eko-baby.ru/userfiles/file/wowazodotiduruxuvetuk.pdfIn PDF document text
    • http://dges.in/userfiles/file/juwanopubamiraxedib.pdfIn PDF document text
    • https://www.singaporemedicalclinic.com/ckfinder/userfiles/files/77679018574.pdfIn PDF document text
    • http://dichvugiayphep.biz/upload/ck/files/womazajatoliduxevun.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/5526365099.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_off0000b178.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB178 15464 bytes
SHA-256: 69e57f6cf8c69ccf402b61a797bfdd20ac2bbb50b6931894f0dce09e36e94117
font_01_sfnt_off0000d8db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DB 10700 bytes
SHA-256: c3378797fb49d4279d6b5681f0c4c410276f277edad143d58530dbc7d1f6c9d3
font_02_sfnt_off0000f12f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF12F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1