Malicious PDF — malware analysis report

Static analysis result for SHA-256 187fb81b81135c6c…

MALICIOUS

PDF

78.9 KB Created: 2021-09-16 15:05:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1a9b2106f6a5d71832cc683dd3da5a2e SHA-1: 4d452e99409f746bc632c7af8d34e7fa5a006979 SHA-256: 187fb81b81135c6cebfa6d2267afd0a68bc8931ce2dd16f950d543f610abef3f
134 Risk Score

Malware Insights

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

The sample is a PDF file flagged as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and a large number of external URLs, many of which are associated with link farms and disposable hosting. The embedded JavaScript and external links likely serve to redirect users to malicious sites or download additional payloads, indicating a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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://allytemp.ru/uplcv?utm_term=free+apk+games+download+offline PDF link annotation
    • https://hijaustabilo.com/contents/files/lojijowilo.pdfIn PDF document text
    • https://smartech.lv/sites/smartech/uploads/documents/files/kupemugisopuk.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///rovizaxugusatoxananipolum.pdfIn PDF document text
    • http://studioambienteterritorio.it/userfiles/files/jodiwiximaxarujikobimise.pdfIn PDF document text
    • http://koutingchina.com/upload/files/gopujelisoxaxazume.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/dekotoloziravulibuzad.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/74422664238.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/file/1631230242_1.pdfIn PDF document text
    • http://xmzs.org/userfiles/file/89899077703.pdfIn PDF document text
    • http://odontoflash.eu/userfiles/files/76702153722.pdfIn PDF document text
    • http://maekalocal.com/Maeka/UserFiles/File/64301745494.pdfIn PDF document text
    • http://shengyaweb.com/uploadfile/file/2021090914451947.pdfIn PDF document text
    • http://spzpoz-zdunskawola.pl/upload/file/jimadogonunixivigu.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/24228005175.pdfIn PDF document text
    • http://falconltd.pl/cache/file/gosetepetosowif.pdfIn PDF document text
    • https://bearings.vn/images/ckeditor/files/30684936576.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/xuwipiwaxi.pdfIn PDF document text
    • https://xn--bankkrtya-41a.hu/js/ckfinder/userfiles/files/noxes.pdfIn PDF document text
    • https://10glazsikeyrosa.ru/file/dobuxoresiwujefad.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/210907174409297286b1fo0e.pdfIn PDF document text
    • http://easy-sleep24.de/shop/images/editorfiles/file/lexipubarix.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/59532763001.pdfIn PDF document text
    • http://speckrepej.com/upload/file/golulowolomiraraxinezuk.pdfIn PDF document text
    • http://fulns.com/uploadfile/fckedit/file/1630930806swk7.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a58aecfdd---nemaxawigoxesafunoxarel.pdfIn PDF document text
    • http://www.tokyomagic.jp/images/library/File/nobovujopoxosum.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_off0000c986.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC986 10900 bytes
SHA-256: e77352887e1b9ca7de1e96552ca92b1aa4d1863676d34a5cf7cdefc20c633123
font_01_sfnt_off0000e286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE286 19468 bytes
SHA-256: f81642fb3856ebf7502926f841a4136b0264a8e929b1540ac257fb0df51702fd
font_02_sfnt_off00011571.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11571 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1