Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f5d378a8cadfd0…

MALICIOUS

PDF

77.2 KB Created: 2021-09-09 12:20:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c3e5def2d84a969d6c2330e30441ab4a SHA-1: fcca640d68358d4291904ad656c572b06586251b SHA-256: a4f5d378a8cadfd07d04162886e273f8848a67391cdd060008c4238788144a0c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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
  • 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://crewmak.ru/uplcv?utm_term=age+calculator+apk PDF link annotation
    • http://tvtamminhphat.com/uploads/userfiles/file/tajupabikidebebit.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/79362473677.pdfIn PDF document text
    • http://herve-coiffure.ci/files/wumesoxuxufedivawob.pdfIn PDF document text
    • https://tsolisp.com/files/file/xaxenajajudimoviro.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613469656c4d1---jekipivenisosatela.pdfIn PDF document text
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/fezokebizusitiloriw.pdfIn PDF document text
    • https://vcubusinesssolutions.com/userfiles/file/tejegu.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16135311a9a3bc---vemimuwumomawiz.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/30441940603.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/27743355161.pdfIn PDF document text
    • http://gymostrov.eu/gymostrov/userfiles/file/ruxojabojatukopajesogip.pdfIn PDF document text
    • https://badeluxe.com/userfiles/files/mobemapusoxekefogo.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/161362eb8412f2---kafosabagivid.pdfIn PDF document text
    • http://bhhangkhong.com/upload/images/files/duvawomesalogukugoze.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/7301d9dcdaae5a3f2e25e6cc22274952/xudesomipigigususinir.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/ruzujevu.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/sapupukujogikebip.pdfIn PDF document text
    • http://laserinnsbruck.com/static/lixelojajuxafujujixufi.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/viwaj.pdfIn PDF document text
    • http://gaushalango.com/uploaded_files/userfiles/files/dokilamituxewaruwefi.pdfIn PDF document text
    • http://dinhviht.com/images/newtech/files/nuwodizilesinomoboso.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_off0000c8ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8CA 10360 bytes
SHA-256: 359d599438c99859cbab4dfe4c0c88e46f05ca498b2e277a420622e450ce1438
font_01_sfnt_off0000e062.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE062 18068 bytes
SHA-256: 843806e64295f5aa5b1da98119853fb06425287e0dda1483a64e2b220b402a12
font_02_sfnt_off00010f7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1