Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a3fe83ce48c417a…

MALICIOUS

PDF

95.5 KB Created: 2021-09-16 16:57:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: db12eeefd990036b7de88007362c9008 SHA-1: 77573aeff425e9fcb5544eeed66eb2663df80dd7 SHA-256: 4a3fe83ce48c417a643af81a0efa1aed9114d53a8480526a89ab793c4f49c0e1
156 Risk Score

Malware Insights

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

The file is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised websites or disposable domains, suggesting a phishing or malware distribution campaign. The PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristic specifically indicates links to compromised WordPress uploads, reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • 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://coretry.ru/uplcv?utm_term=aprender+maya+pdf PDF link annotation
    • http://mdsalon.ru/img/lib/file/90260172796.pdfIn PDF document text
    • https://arerp.kr/data/file///nerovigow.pdfIn PDF document text
    • http://abwrichmond.com/uploads/files/40701090549.pdfIn PDF document text
    • http://gruaszarate.com/ckfinder/userfiles/files/jexipusozisa.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/ludinamikaxukibaxizisila.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/warikirufafelegodusatu.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/1840502611.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/6134f0ded4d79.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/vejutafeguwovufe.pdfIn PDF document text
    • http://dekogard.net/deko/veri/_files/gasalimivirepivudoji.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/d5c2eb13bf5900ecfc957216649dd274/8166978541.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/92757491203.pdfIn PDF document text
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/72497326659.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/lasuxisonezunevipixutapu.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f88f44b6e3---pizobakitapapijopukuweseg.pdfIn PDF document text
    • http://studiotecnicopetrillo.eu/userfiles/files/76792899724.pdfIn PDF document text
    • https://umutisi.com/umut/upload/files/mulikizokased.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/meximerelefopo.pdfIn PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/fukowizukos.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/vatozaxipevep.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614122b515a8f---22368894546.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/a05027685ad26e8b3ec35cd7061c8832/47200802022.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/jemivipi.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_off00010ea0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA0 20240 bytes
SHA-256: e6742de8862f39d4138479a3c754cd38b2fef21ff5d75a35f87a7435bb9978d2
font_01_sfnt_off000141d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141D0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000159e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x159E7 10232 bytes
SHA-256: c3ae84acf6f14159d843af0a72b178ea2aeb357765773d6023d9e98ee019f57e