Malicious PDF — malware analysis report

Static analysis result for SHA-256 de4a51eda6cdd8d3…

MALICIOUS

PDF

78.7 KB Created: 2021-09-24 02:17:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c0f0acc0f5b783d46b8e981e20b54fa5 SHA-1: 0f02b3a46b4060c0187e518a9fb81480a05067cd SHA-256: de4a51eda6cdd8d3d81593d149a4d8089d449beaedbe46591433b90362da4a40
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs, while numerous, are the primary indicators of the attack pattern, directing users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc4047ae22---jifemabawu.pdf In PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/tri288bnt80bijprmnj6b5koj5/rigamaxit.pdfIn PDF document text
    • http://eaas-journal.org/survey/userfiles/files/13139293283.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/62946848588.pdfIn PDF document text
    • https://sandipkumardutta.com/ckfinder/userfiles/files/10338607156.pdfIn PDF document text
    • http://deforma.it/userfiles/files/pozavemexi.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/jezem.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/jibafusajawitakodisili.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410cf2a7aab---vijopej.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/12404313472.pdfIn PDF document text
    • https://journeywithmypet.com/ckfinder/userfiles/files/16477586915.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/79773641642.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/fovozawelamigul.pdfIn PDF document text
    • http://cungcapbaoduongcuanhatban.com/upload/files/xibogiro.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161492c2bc2da2---7809972185.pdfIn PDF document text
    • http://kjphotocon.org/data/userfiles/files/vurij.pdfIn PDF document text
    • http://baove247.org/upload/files/6058602394.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/pewudesazobedomatekotufo.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210912173831.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134dd1764933---kijefifegezo.pdfIn PDF document text
    • http://nieruchomosciklodzko.pl/files/file/5325544285.pdfIn PDF document text
    • http://tornyanggrace.com/upload/file/891812820.pdfIn PDF document text
    • https://luatkhangthai.vn/upload/fck/file/vidarerojuxizip.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///2021916215836560.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=android+tv+freebox+revolutionPDF 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_off0000d0a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e8b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B5 17236 bytes
SHA-256: 4f7a6f4a4ff51065a4799d94ac3f2610069e5aece674492694b224231f133c10
font_02_sfnt_off0001156e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1156E 10408 bytes
SHA-256: 5d9273f53760c4cc27d7d05fb6ecaf73b51008452a7f40a7a65042f337e4f8aa