Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31f42fc7b99063e…

MALICIOUS

PDF

71.4 KB Created: 2021-09-26 19:28:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dd260b4bcaafbf639ab6d94eca47fe54 SHA-1: de2440f97a7de602239a2d43879e68eeeabdf809 SHA-256: f31f42fc7b99063e370f35313edb8dcaee98aa100233d897c8052c06146e9be3
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high ML score and ClamAV detection for a phishing trojan. It contains a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to redirect users to malicious content. The document body is unreadable, but the presence of numerous links indicates a likely phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://trvstore.com/userfiles/file/maxajorimevawimazuvozujo.pdf In PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb4122f3c6---15764058265.pdfIn PDF document text
    • https://maturana.cl/upload/file/97809782774.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/9969018247.pdfIn PDF document text
    • https://lalicorne-hotel.com/userfiles/file/24665882922.pdfIn PDF document text
    • https://marmetal.cevhertemizlik.com/userfiles/files/malunudobopem.pdfIn PDF document text
    • http://daejonggyoyc.com/userfiles/file/20210917112616.pdfIn PDF document text
    • http://korytnica.net/data/files/12812440819.pdfIn PDF document text
    • https://maciejabramowicz.pl/upload/files/file/zoronefovagadowegurebokuj.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/ddb962d61f8105717932ba5cfa0c40b9/dugozizoj.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210905_91DE4566AD27C390.pdfIn PDF document text
    • http://jindi2010.com/uploadfile/files/nivewepovek.pdfIn PDF document text
    • http://motolargo.pl/userfiles/file/52979563564.pdfIn PDF document text
    • http://cnmrobotics.com/files/files/44076724512.pdfIn PDF document text
    • http://xn--h1agcmh.com/ckfinder/userfiles/files/wetukirez.pdfIn PDF document text
    • http://traslochimontalto.it/userfiles/files/fefefuvukimumudegufo.pdfIn PDF document text
    • https://protum.se/file/44141057489.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/17946320121.pdfIn PDF document text
    • https://aznamaste.com/ckfinder/userfiles/files/ditikalonuvodetevo.pdfIn PDF document text
    • http://yuilchem.com/userData/board/file/xuwowuluwesegozujetoxaked.pdfIn PDF document text
    • https://triosms.com/userfiles/file/88982257823.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac1f7a1a46---14139323400.pdfIn PDF document text
    • http://pizzeriadevita.it/userfiles/files/75362277095.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=play+store+top+rated+gamesPDF 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_off0000b29a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB29A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAB1 10652 bytes
SHA-256: 13f89821b215fe31aa433b3d6d9418ada00a206b0539a4a332d14714d7a8b033
font_02_sfnt_off0000e2ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2FF 17304 bytes
SHA-256: 61ed5c3294d2c4113016f76c941ccd4ed8ece95fa7193cd4f60a5895850b493c