Malicious PDF — malware analysis report

Static analysis result for SHA-256 0e03922e03be21d6…

MALICIOUS

PDF

69.0 KB Created: 2021-10-02 18:46:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c68231ffd77adfd212dca0c7ec59ce88 SHA-1: 4c34a04063b47a9bfd5155dd54d7baeffb04e0c7 SHA-256: 0e03922e03be21d60ee4746caf7c7b8df9759a13936079f165876ab6746ba0ab
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files hosted on various domains, some of which appear to be compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://reichspfarrer.sk/file/xavinusigof.pdf In PDF document text
    • https://vr-spagna-20.effievirtual.com/galeria/files/vexaxonefileko.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/rurowutagoka.pdfIn PDF document text
    • http://sreema.org/FCKeditor/file/38754253535.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140263613338---mubevasugujevimotuwu.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/37589596130.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/6377e535fbb90ed327e3b79f4b9b77e2/30370644085.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161363daa95159---duzisipupa.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/e73511a1458cf2514d0cb522926a9783/21411290428.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/zedunirelilagakazumefano.pdfIn PDF document text
    • http://lsbwg.com/ckfinder/userfiles/files/20210919/1705453619.pdfIn PDF document text
    • http://lighthouse-connection.at/myPix/file/dopewisoxoxis.pdfIn PDF document text
    • https://www.info-service.com.tw/plugin/ckeditor/ckfinder/userfiles/files/kipokugezuxapi.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/xolugine.pdfIn PDF document text
    • http://ferrogep99.hu/static/media/file/meziwaxiwez.pdfIn PDF document text
    • http://kdsonline.org/userfiles/file/litalulofusarelorizusi.pdfIn PDF document text
    • http://konferencii.org/web/uploads/assets/file/womororakowivaruvo.pdfIn PDF document text
    • http://sql110.com/pic/31439136148.pdfIn PDF document text
    • https://zoorichi.com/temp/fckeditor/file/71599484957.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/38991765075.pdfIn PDF document text
    • http://syntra.pl/userfiles/file/rexadutosabekixidoduju.pdfIn PDF document text
    • http://china-hold.com/UploadFile/file/20210922201745290.pdfIn PDF document text
    • http://karlsbach.de/userfiles/files/mizojexujigu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=what+colour+does+red+and+brown+makePDF 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_off0000ae25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE25 15376 bytes
SHA-256: 5743ce4fb9902859bf3d040bf30961a972a3e290d66fd1254e56602cc5f07b8f
font_01_sfnt_off0000d514.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD514 10952 bytes
SHA-256: 7f4022b1f884b80d9f5790cda83bf87932471edfc62d35d694dd2fb6c6e3651d
font_02_sfnt_off0000ee6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1