Malicious PDF — malware analysis report

Static analysis result for SHA-256 38663ad70be54a62…

MALICIOUS

PDF

79.0 KB Created: 2021-09-12 02:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 11dacd1252902ce0ebe795eb7fe02b47 SHA-1: f7cb4ca6ae4096824518a5ec953e1432e3cef417 SHA-256: 38663ad70be54a62d8c064b858e3671bb339bf79c3933e897e681e5c39c77e4f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. These link farms appear to be designed to obscure the ultimate destination, with one heuristic specifically identifying a 'link farm on disposable hosting'. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution via these redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16132bea6cf4f1---32489675602.pdf In PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/44456114621.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/tinomodo.pdfIn PDF document text
    • http://qwerty.pl/_data/file/14620314947.pdfIn PDF document text
    • https://kamwalibais.com/userfiles/file/durisevalakado.pdfIn PDF document text
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/20302090736.pdfIn PDF document text
    • http://novena99.com/uploads/files/202109081653409086.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210904154806.pdfIn PDF document text
    • http://netcentricnj.com/ckfinder/userfiles/files/zikusifikudow.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/ad8892d0a083c0a28c1eb0673e4941e2/notazuteko.pdfIn PDF document text
    • http://hqshop24.com/userfiles/file/97816461061.pdfIn PDF document text
    • http://inruho.ru/ckfinder/userfiles/files/fodetepuromuwavedife.pdfIn PDF document text
    • https://etadelloro.it/images/file/28646336546.pdfIn PDF document text
    • http://tsyrulnikov.ru/upload/file/wonajofitegidoxuk.pdfIn PDF document text
    • http://proart.by/media/file/85606276437.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/61595924241.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/161372f5041758---wudiramire.pdfIn PDF document text
    • https://perfectsextherapy.com/public_html/userfiles/file/93056245379.pdfIn PDF document text
    • http://dr-onesrl.com/userfiles/files/96704495923.pdfIn PDF document text
    • http://hanleyresources.com/images/13327107155.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/lurasebusariginivavixuzam.pdfIn PDF document text
    • https://mclandpin.com/calisma2/files/uploads/favibogabefol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+to+flash+twrp+without+pcPDF 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://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_off0000d253.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD253 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA6A 10520 bytes
SHA-256: a30e6b63582b8fc3737a56c3a42477eaa7b3289b5d8c1453a17e49e50c5bbb2f
font_02_sfnt_off00010284.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10284 17996 bytes
SHA-256: c88f9ac178ff0f7dc96044147631d58a3e7386d05e0d386af7a99fd4ae19e476