Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bc320c90f393eb4…

MALICIOUS

PDF

82.8 KB Created: 2021-09-15 21:52:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 2022b250aff5cbea89f00de5e0af3e56 SHA-1: 8c273dfe2d9890e261f7b90082b0496a9a069387 SHA-256: 3bc320c90f393eb4b265bf16496901b0bb6efcd3202ccb33f9063f1eb9f45e02
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://catamma.ru/uplcv?utm_term=android+app+store+free+paid+apps PDF link annotation
    • http://lmnn.ru/userfiles/file/23694617278.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/ka6c9017538cm3ml6oskke6qv3/83612871740.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613ebfcbf140a---19810502632.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-3/20210903052003839175.pdfIn PDF document text
    • https://acrgruppe.de/userfiles/file/49841979259.pdfIn PDF document text
    • https://ayurmitra.com/files/file/wefirovi.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/161406f5aa8e70---sugumad.pdfIn PDF document text
    • http://maxidmum.com/images/upload/fck/file/jepidapodanirijivom.pdfIn PDF document text
    • http://sambometal.com/dataroom/file/relef.pdfIn PDF document text
    • http://vagtteam.dk/userfiles/Files/desemoradoxoziradoz.pdfIn PDF document text
    • http://optimaglobal.net/ckupload/files/vubedomudisunexeponanexus.pdfIn PDF document text
    • http://captainkillmite.com/uploads/files/202109080425576662.pdfIn PDF document text
    • http://yonezawanet.jp/units/24250/zcycom/files/69455205460.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/loxujap.pdfIn PDF document text
    • http://freeware-software-download.de/uploads/editor/file/fakanuz.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614130204ba15---nunojurobutuxu.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/66653984790.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/zaribetatida.pdfIn PDF document text
    • http://queenart.kr/userData/board/file/tajizolebamosi.pdfIn PDF document text
    • https://newdesert.pl/userfiles/file/kuzixakezivijejap.pdfIn PDF document text
    • http://z-i-f.ru/userfiles/file/vikowifazegulusajagev.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_off0000e089.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE089 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f89b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89B 17608 bytes
SHA-256: 30ddab718dfb415273c0de14cbeec0a0a35d26ad7328ac7813d2a187c4ccebb3
font_02_sfnt_off000125d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125D1 10428 bytes
SHA-256: 5e3cdc52cd89108d83cd5d63b861efe43312ac7db8709ea2698e254dd64e7472