Malicious PDF — malware analysis report

Static analysis result for SHA-256 76acf3f247af4092…

MALICIOUS

PDF

82.7 KB Created: 2021-09-17 18:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2a37243c745573a63e94320d77140b2e SHA-1: 967da6de138ee1d0138779255dad26ad1a6c53d2 SHA-256: 76acf3f247af40929148afc440a2ef5e352eff42fa2790616994997211d65ce5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a common technique for distributing malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://crewmak.ru/uplcv?utm_term=samsung+galaxy+tab+s6+teardown PDF link annotation
    • https://rarahil.org.np/ckfinder/userfiles/files/tifivojuziwej.pdfIn PDF document text
    • http://cn-noah.com/uploadfile/file/vamakos.pdfIn PDF document text
    • http://csc020.com/userfiles/file/20210906121443_rs8g3r.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/06173612196.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/21599836341.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/wosezexa.pdfIn PDF document text
    • http://novichiha.ru/pic/file/50177316221.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/30290505311.pdfIn PDF document text
    • https://maurinet.com/userfiles/file/zujuxurokixisadume.pdfIn PDF document text
    • http://haiqi-machine.com/d/files/serexer.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f9b2eb69b3---18058071906.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143480fb4ec1---88007594324.pdfIn PDF document text
    • http://trust-law-firm.com/userfiles/file/20210911142932_506116834.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/0f7df6e776bf555553bf4cc967d705a8/27905345476.pdfIn PDF document text
    • http://gardens-spa.com/user_pict/file/86863192467.pdfIn PDF document text
    • https://masukpt1.com/contents/files/xozotefebevesatigagosa.pdfIn PDF document text
    • http://classicalgardenornaments.com/uplds/file/60035752343.pdfIn PDF document text
    • https://kotata-zlin.cz/obr/clanky/file/dixexeralolofubakuwuju.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/694564d29952048a03ee10e8cd8f5fdb/8688278680.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132b2de46cb9---22692828991.pdfIn PDF document text
    • https://ingatlansos.hu/images/userfiles/file/38360689074.pdfIn PDF document text
    • http://ux-school.ru/files/files/8984055267.pdfIn PDF document text
    • 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_off0000db5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB5E 11284 bytes
SHA-256: b2c2fbc7d97d177e3bc77d337ece34b9dc38a5ce3a027cc74639685c796df88f
font_01_sfnt_off0000f5c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C2 18148 bytes
SHA-256: 2d5a5c7fa9d928ef25d82b31facd670acd21af55cb54ca23813a49bd93a88892
font_02_sfnt_off0001251f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1251F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1