Malicious PDF — malware analysis report

Static analysis result for SHA-256 7e7efce9fb5e7cc1…

MALICIOUS

PDF

68.6 KB Created: 2021-09-20 10:01:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0e6c31034441360415987e3f6f715736 SHA-1: f82ee000c8c93c893ad4236eb9099bdf99e10c60 SHA-256: 7e7efce9fb5e7cc186027b9f68ee52b7c18ad6d82cdcd42e3346a1e3f8eb4f38
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by a ClamAV signature and an ML classifier, indicating a phishing or trojan-like behavior. The heuristics reveal it functions as a link farm, hosting numerous links on compromised CMS uploads and disposable domains, likely to obfuscate malicious destinations. The embedded URLs and the nature of the link farm suggest an attempt to lure users to external sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613352044f2cb---5306680741.pdf In PDF document text
    • http://nhadephoanhao.vn/upload/ckupload/files/saxumejapiz.pdfIn PDF document text
    • http://fcgo.tw/uploadpic/files/19609998132.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/79932577677.pdfIn PDF document text
    • https://homeuu.biz/upload/ckeditor/pages/files/radakidupevexaten.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/laxaxelomigexetiki.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/34041841503.pdfIn PDF document text
    • https://wtmasonry.com/ckfinder/userfiles/files/xanoxojezifexawonofalena.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c70668ff79---41486366645.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/99549992211.pdfIn PDF document text
    • http://cmi.nfe.go.th/ckfinder/userfiles/files/38527712398.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/juzipineboda.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/9ebd2ce8e5e79d8b4b84de545d375203/26244576029.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210906092112.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/2021915_152034_252.pdfIn PDF document text
    • https://luatsubienhoa.com/upload/ck/files/47344480722.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/gogodarirujafelukit.pdfIn PDF document text
    • http://ausafe.net/images/art/files/10557783268.pdfIn PDF document text
    • http://osstemcardiotec.com/files/fckeditor/file/1879539834613faa71be062.pdfIn PDF document text
    • http://julianina.dk/upload/file/8658533622.pdfIn PDF document text
    • http://speckrepeg.by/UserFiles/files/mivaxarawawa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=delete+all+sms+messages+androidPDF 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_off0000ade5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADE5 15292 bytes
SHA-256: edc369837684c5c4bffab31bd927c763cdca5fa35fdefc002e8ff7afca4fc3de
font_01_sfnt_off0000d4e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ecfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECFD 10592 bytes
SHA-256: f0fe2272448efc544d72b79e25d548d48ee6c247123219669114ed2abe36085c