Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca853cb20cde9862…

MALICIOUS

PDF

72.4 KB Created: 2021-09-17 06:26:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 889b95f44d27bd1c8682498af48c9133 SHA-1: 32149d1ff6f8276b238f730bc5ae0a5943d1ba85 SHA-256: ca853cb20cde9862733114c71e80bf8b7eaeed5ecdc9e90e3c07565d3bc5b166
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous external URLs pointing to various domains. Several of these domains are identified as potentially compromised CMS upload storage or disposable hosting, suggesting an attempt to obscure the ultimate destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://deitratech.com/userfiles/file/55260555268.pdf In PDF document text
    • https://alternativecarrepair.com/userfiles/file/namiludobazubufideroxada.pdfIn PDF document text
    • http://demo-jesma.shopcloud.es/ckfinder/userfiles/files/68104421832.pdfIn PDF document text
    • http://sydjpg.com/images/upload/file/20210908_165628_143.pdfIn PDF document text
    • https://qnzar.com/files/mijumu.pdfIn PDF document text
    • http://peter-scherer.de/userfiles/file/28181624555.pdfIn PDF document text
    • http://wellfoto.cz/pictures/files/77251427102.pdfIn PDF document text
    • http://seidels-mineralienwelt.de/images/uploaded/file/nufepujetagakasekamagar.pdfIn PDF document text
    • http://rungruangsteel.com/public/upload/userfiles/files/18984802146.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/bipawidofemefemufepawefu.pdfIn PDF document text
    • https://rintrans.com/files/82111758536.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143371d23cfc.pdfIn PDF document text
    • http://dennehylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30077190705.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b06678c188---gipalogofexuwifoxamup.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/512cc9bb19320d3c06ab08c569775a70/5176468967.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/71042402035.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/lukukat.pdfIn PDF document text
    • https://cepatdaftargroup2.com/contents/files/78380600177.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4571f1b40---gefabal.pdfIn PDF document text
    • http://etyekilovarda.hu/userfiles/file/xugifejuxategoni.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/9221679407.pdfIn PDF document text
    • http://santehnika34.ru/images/file/65383952567.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/rutulaj.pdfIn PDF document text
    • http://liqaa-lb.com/files/userfiles/files/44133227968.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/92107283614.pdfIn PDF document text
    • http://conganbacgiang.vn/app/webroot/uploads/files/sojubepoxik.pdfIn PDF document text
    • http://derkwoo.com/upload/editor/files/wiwosesewalaxunek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=fb+lite+mod+no+load+apk+downloadPDF 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_off0000b8da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8DA 16428 bytes
SHA-256: 023de27db4e8de70006b77b7758d0152ba573e9f4a1f35d8d760aafb666261e9
font_01_sfnt_off0000e336.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE336 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB4D 10580 bytes
SHA-256: 6844594bad69792e7d3e59cf1e59352d06b27bec9075b8c2cb62fb4576554670