Malicious PDF — malware analysis report

Static analysis result for SHA-256 721aef8afb72ca1e…

MALICIOUS

PDF

77.7 KB Created: 2021-06-10 16:05:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 731a7a358751c5a7b35fe64f5989d784 SHA-1: e03965c4de0ad2bd2330a314fbf11e14a87d2105 SHA-256: 721aef8afb72ca1ed20452e5f5cb458e27a58151783476fb715ea80992efbf8d
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier strongly indicated maliciousness, and the PDF structure suggests a link farm designed to redirect users to potentially harmful content. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirm the malicious intent of directing users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://synerhu.ru/uplcv?utm_term=building+material+prices+2020 PDF link annotation
    • http://alphabodysupplements.com/newerac2c/userfiles/file/79457914602.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160902eb774fa1---lowikekifawitipiw.pdfIn PDF document text
    • http://askort.pl/Upload/file/45974968477.pdfIn PDF document text
    • http://21cedu.com/pds/userfiles/files/21593962802.pdfIn PDF document text
    • https://daxitrip.com/basefile/daxitripcom/files/silivoratefapenamu.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/hfk3ki9o8i6906sdt0gqctqs9t/wowamixilavizoti.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16077c173a3a88---mumafomoku.pdfIn PDF document text
    • http://changdahk.com/upload/wasikinobupufebazoji.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607559fad17a3---vukafe.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad1b738e770---86546760428.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160accea8a8fad---32827075310.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16079dab2de7a0---82296754922.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/7j3mea0227lpiskmfmtul1dnl6/81704201466.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5edcebcdb---57164198505.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/eiib9sgei0ad2ma00rsrlmgeqt/96111584852.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/f101e5c950d0486b52f7a96992d5513a/refawubisume.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160784945ea8b9---45031965493.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A5 5488 bytes
SHA-256: 4b973894aeb105c2aa25e6360307ba70f83036d68dfa1e19bc4eeb10df900ab4
font_01_sfnt_off0000f528.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF528 10960 bytes
SHA-256: 52212a66d80451716c999f33e7b410374a63c0e96c310a9fdfcb677f2ff08e33
font_02_sfnt_off00011a04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A04 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c