Malicious PDF — malware analysis report

Static analysis result for SHA-256 b381a3c8d1ac4633…

MALICIOUS

PDF

82.2 KB Created: 2021-10-06 00:16:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ba4c9dd2b9aed952fdc2a58f76266fed SHA-1: ee82d0b5863467955e4b180938a20c3395c47e2f SHA-256: b381a3c8d1ac4633d0c547dc987ba48b3e593ef6dbc815c74a7d0c80946f171c
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple URLs pointing to potentially compromised or disposable hosting. The presence of numerous links, including one hosted on a compromised CMS upload storage, suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://bda.ch/ckfinder/userfiles/files/70291563944.pdf In PDF document text
    • http://www.bordadoindustrial.com/ckfinder/userfiles/files/17950091349.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210928192314527.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/tukemabazijisusumokerime.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/87777810082.pdfIn PDF document text
    • https://bonekarusa.com/contents/files/majavameroxoledugis.pdfIn PDF document text
    • https://ngenadmin2.nextgenphotosolutions-beta.com/app/webroot/files/file/70022990988.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/3ef3b17c2a4f234de275b2044f1947e4/43790565681.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/sogebunorev.pdfIn PDF document text
    • http://border-collie.ru/sites/default/files/file/zitaputedisoxazezekenix.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/nofozavorazasozilu.pdfIn PDF document text
    • http://qcfloor.com/userfiles/file/34001780.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210922025145.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/24365684688.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c06a956be6---9038501027.pdfIn PDF document text
    • https://playindiano1.in/ckfinder/userfiles/files/danejigosafemiwo.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161441dfa8e8eb---87819303623.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/3eb38one98bt7do5ia0jolj6il/17392570553.pdfIn PDF document text
    • https://junona.manyel.website/images/uploads/medium/32056918214.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/biwowu.pdfIn PDF document text
    • https://mrpressconsulting.com/UserFiles/file/givexokavabuba.pdfIn PDF document text
    • http://dae-young.kr/upload/fckeditor/file/80956699442.pdfIn PDF document text
    • https://virtrade.gr/userfiles_lybo/file/luturala.pdfIn PDF document text
    • https://strefaokazji.pl/uploaded/file/nozesubi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=application+letter+for+the+post+of+office+assistantPDF 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_off0000df19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF19 10560 bytes
SHA-256: 8858e2eb7983b55109d748b070fd18ad84a184851c6db3721f15589715868211
font_01_sfnt_off0000f72e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72E 16812 bytes
SHA-256: e1f02c008317f320a656163ad824d96259470043715fe15bfd631c169c3acc5a
font_02_sfnt_off000122bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1