Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c7c3c370ad124c…

MALICIOUS

PDF

88.6 KB Created: 2021-09-22 17:14:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: d5e28832dc5bd6a055da15d4608e947d SHA-1: 073b2eba680975a4ba16dfa5297858020779e4cd SHA-256: a4c7c3c370ad124c10bf7de2b7c12a7a00e334d82aa0f237b39832e7b3d2f6eb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics, including a high ML score and ClamAV detection, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically points to the document acting as a link farm, directing users to numerous distinct hosts. While no scripts were extracted, the presence of many embedded URLs suggests the primary function is to redirect users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • 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.
  • 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://drhuanghair.com/uploads/files/202109010756541174.pdf In PDF document text
    • https://bangprice.com/bangprice.com/beta/cms_image/file/2259598437.pdfIn PDF document text
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/zukaxeveturubikilobimekod.pdfIn PDF document text
    • https://mimpi1pusat.com/contents/files/wagutul.pdfIn PDF document text
    • http://baltic-rt.ru/ckfinder/userfiles/files/21048165079.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/kobaxalazunodel.pdfIn PDF document text
    • http://retrofitoman.com/ckfinder/userfiles/files/nafojajamilusiw.pdfIn PDF document text
    • http://ya-ke.cn/admin/upload/numokobiwisizolafu.pdfIn PDF document text
    • http://csigikes.hu/admin/fck_upload/file/33389909915.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/xorupisakenolimoga.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/nilugiwituwine.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/32666546418.pdfIn PDF document text
    • https://fiscalonline.ro/app/webroot/files/userfiles/files/20020012241.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/66032213268.pdfIn PDF document text
    • https://rapn.ru/ckfinder/userfiles/files/nanesuj.pdfIn PDF document text
    • http://gemmacapitalgroup.com/foto/file/28613656225.pdfIn PDF document text
    • https://bluetact.com/ckfinder/userfiles/files/vedowoxijow.pdfIn PDF document text
    • https://nycsmindia.org/ckfinder/userfiles/files/pobujirunajudejiwifi.pdfIn PDF document text
    • http://sk4education.com/ckfinder/userfiles/files/nulexeruze.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/46401942653.pdfIn PDF document text
    • https://broadcasthub.com/ci/userfiles/files/raziwid.pdfIn PDF document text
    • http://myucpb.com/userfiles/file/95801990409.pdfIn PDF document text
    • https://sapsda.org/SapmaUserfiles/file/togagesaja.pdfIn PDF document text
    • http://tonyprins.nl/images/uploads/file/jolewo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=good+android+emulator+for+pcPDF 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_off0000f684.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF684 17536 bytes
SHA-256: 7f67d5b88c64fff6755788acc68f51da3fb8d9d6b52c0894e552c948fcb45e24
font_01_sfnt_off000123a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123A9 10752 bytes
SHA-256: 34e2a05f4edee6eced9f93445edd8b31935a8f3cc0d80dde65a7d5373161af07
font_02_sfnt_off00013c5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C5C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1