Malicious PDF — malware analysis report

Static analysis result for SHA-256 da8dbf1358ce539f…

MALICIOUS

PDF

90.6 KB Created: 2021-09-23 15:26:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e4cef199c73f92ee2bfdb70d745673f7 SHA-1: fe79303786a9597583cfb0ee859f60212a86a18f SHA-256: da8dbf1358ce539fdc1a94a5e892e11f7a3fb8d2df4b831d894e6a8778f92865
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The presence of multiple unknown URLs further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://hydrem.ru/images/file/3157078982.pdf In PDF document text
    • http://kamnitikamini.si/upload/files/rusonokazareluwade.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/6388953486.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16134d8e452981---nagenolegukupawobi.pdfIn PDF document text
    • http://lobi.md/userfiles/file/91287577570.pdfIn PDF document text
    • http://stihoplet.by/upload/editor/files/71066252151.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/93564355781.pdfIn PDF document text
    • https://i-intelli.com/ckfinder/userfiles/files/57340115355.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210917005234_yxf56l.pdfIn PDF document text
    • http://iaestedresden.de/userfiles/file/xogimitigiluso.pdfIn PDF document text
    • http://thelonerangerfanclub.com/ckfinder/userfiles/files/mefofujufidiravokenexudum.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/53289697840.pdfIn PDF document text
    • https://doosradashak.in/ci/userfiles/files/juvigi.pdfIn PDF document text
    • https://piphoto.tw/uploads/files/202109191722575809.pdfIn PDF document text
    • http://adwokaci-pila.pl/userfiles/file/gonafevaja.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/kopilirobobelutipusumoza.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131b0aa8299f---68727439106.pdfIn PDF document text
    • http://hotelniagararimini.eu/userfiles/files/23527502515.pdfIn PDF document text
    • http://sun-apartments.pl/data/pages/92773590475.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/tafenewimepoganafer.pdfIn PDF document text
    • http://adacu.org/userfiles/file/20210917182355.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/dejebu.pdfIn PDF document text
    • https://el-tall.pl/pics/file/degipanitadawa.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148143b7c22e---jidapawinuzudaxojen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=the+walking+dead+s10e11+torrentPDF 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_off0000f693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF693 20820 bytes
SHA-256: 65f15d37202885f21f182953c570741771bcf6fec95fe4f6665e577835a19eda
font_01_sfnt_off00012bc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BC3 10840 bytes
SHA-256: 94009d4aa815dec99692525fb3c985cd4fa7d808be2420cfbde5d096bda7cd5d
font_02_sfnt_off0001449f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1449F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1