Malicious PDF — malware analysis report

Static analysis result for SHA-256 e38e936b7c4e23f0…

MALICIOUS

PDF

82.1 KB Created: 2021-10-08 03:45:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 3f1166a5eba92063928424c6671ef953 SHA-1: 699cdff6cc1b75073f59b712b8fe523272f1820f SHA-256: e38e936b7c4e23f0692f80a02da62f96e30ba4b96fffcd572f86fbfedf29cdeb
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 websites or are part of link farms designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is unreadable, but the heuristics and URLs are sufficient to infer a malicious link-farming attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://silarperu.com/UserFiles/file/gazobogup.pdf In PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/dogute.pdfIn PDF document text
    • https://tidurmalam.com/contents/files/24044379000.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/duvovesigarimutovisifil.pdfIn PDF document text
    • https://phucatgarment.com.vn/ckfinder/userfiles/files/1136756074.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/43465477327.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614b485520abf---masilezifitovejusu.pdfIn PDF document text
    • http://expertsystemgroup.com/file_media/file_image/file/patas.pdfIn PDF document text
    • http://jiehuist.com/userfiles/files/10753266209.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/36702186459.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/39atrhmcc6phou3hnrmdvb89pc/vexatuwa.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/pevoxujofuweribefunopex.pdfIn PDF document text
    • http://statsale.com/data/upload/ck/files/72257072528.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/94026753413.pdfIn PDF document text
    • https://ln80.cn/filespath/files/20210911150152.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158bb990b314---31029735019.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153f381903ec---zivalarozuwevagulafe.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/342qqoo6r51q6itmv0jpq7ndof/vomemixudi.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/16800827398.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/30568555929.pdfIn PDF document text
    • https://sunridgecorp.com/uploads/files/202110011405372782.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=endocrine+glands+present+in+human+bodyPDF 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_off0000d70d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD70D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1F 19220 bytes
SHA-256: 992ce33aca5b0b195a66862de16bb2bd4f82e9580828215569d3cad598e16229
font_02_sfnt_off00012112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12112 11296 bytes
SHA-256: f8bb74f54fef3a84cbeda51979329bb59f7b5809d2e9b7b2aec5c08206910f6f