Malicious PDF — malware analysis report

Static analysis result for SHA-256 138410fe0346e5d6…

MALICIOUS

PDF

72.9 KB Created: 2021-09-06 22:12:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 673cbb702a21128b76510f330d4b9439 SHA-1: 85655789b8af6ea9ee1f9d30f636a0d5cdbddcaa SHA-256: 138410fe0346e5d6db7dc3bdb0f573ceca00f6b46c93fdcea3be2509b981694f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs. It also contains numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c730152e7d---nikatomisarovugoxazaloka.pdf In PDF document text
    • https://brothers-music.com/ckfinder/userfiles/files/47416785002.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/13192722617.pdfIn PDF document text
    • http://walkercombsfamilyreunion.com/clients/d/df/dfd517ab040340b2551da60fba195f5f/File/daroveki.pdfIn PDF document text
    • https://crownprolaw.com/userfiles/Proj_Name/files/kofekosinaxalikotisawuw.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b59f8a08655---37363289420.pdfIn PDF document text
    • http://emblem4home.com/UserFiles/Member/File/rijiwudijed.pdfIn PDF document text
    • https://semut73.com/contents//files/zotoranotipi.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfa107b1a9f---29940598203.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/oh4baqaic2apl3gqcc6gvk43ji/ditetikilabupuro.pdfIn PDF document text
    • http://tsutae-f.com/js/upload/files/zizodun.pdfIn PDF document text
    • https://willmarareachamber.com/ckfinder/userfiles/files/jepavejebovadepumox.pdfIn PDF document text
    • https://ckmandarin.com/uploads/fuxif.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f596dd0bf2---58688214239.pdfIn PDF document text
    • https://www.jdconstinc.com/ckfinder/userfiles/files/86253372299.pdfIn PDF document text
    • https://cebrigantina.com/025-CEB/images-editor/file/xubes.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16077b96a1fa5f---filaz.pdfIn PDF document text
    • http://sevenseahotel.com/uploads/images/files/39460806065.pdfIn PDF document text
    • http://chongros.com/userData/board/file/98141390105.pdfIn PDF document text
    • https://syteq-pro.com/userfiles/file/tuxolorob.pdfIn PDF document text
    • http://cesurmakina.com/userfiles/file/17232583501.pdfIn PDF document text
    • http://fontanarosaserigrafia.it/userfiles/file/lezavinibosoxulisetowukuf.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd0a642df74---2984200846.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=tamil+puranam+books+pdfPDF 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_off0000bab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAB9 16596 bytes
SHA-256: 600b00bb3d3888998f965a22a5328c3ae73385cebc395a1c5de65d7d63196bc9
font_01_sfnt_off0000e5ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fdc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC3 10724 bytes
SHA-256: 32093653df3ceeeb924015cb339228cce5139d83d1e26cd7ef18b4eb1c7615a1