Malicious PDF — malware analysis report

Static analysis result for SHA-256 7db7df0af0a2f7dc…

MALICIOUS

PDF

72.0 KB Created: 2021-09-14 10:21:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e0c835e79cecdb0f479f30d5d7349b28 SHA-1: b0aed7334b78ba22324b8da15a9b3d1c4d4b8662 SHA-256: 7db7df0af0a2f7dc0b68418a071345622000384b00715780a24609536e1ded8b
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, so the primary attack vector appears to be social engineering via malicious links.

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 https://krisoc.ru/uplcv?utm_term=download+super+mario+bros+nds PDF link annotation
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138175b377f6---99314996487.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/73142783577.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/161401267b103e---7627767900.pdfIn PDF document text
    • https://proia.bg/userfiles/file/72907294454.pdfIn PDF document text
    • https://bloomeng.com/uploads/wovezisasavonuw.pdfIn PDF document text
    • http://chenruichem.com/upload/files/bamobomulixanufibu.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/85279958382.pdfIn PDF document text
    • https://sayurmateng.com/contents/files/71830542469.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/36052315537.pdfIn PDF document text
    • http://gojjang.com/uploads/files/gulufapoxot.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/31995712412.pdfIn PDF document text
    • http://imaginove.eu/data/Files/nijokadeligizamufoze.pdfIn PDF document text
    • http://186086.com/upload/files/sosamumetabu.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/bitilodupezapuxezig.pdfIn PDF document text
    • https://democv.associasuite.com/imagenes/contenidos/files/nugavejidulepedivib.pdfIn PDF document text
    • http://dienlanhtruongson.com/upload/files/58228420831.pdfIn PDF document text
    • http://gojjang.com/uploads/files/32645457169.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109121711497076.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/dnbblk12nhabdusiulhfqcb481/bufuf.pdfIn PDF document text
    • http://stsaischoolamritsar.com/slbdavbatala/userfiles/file/budawetotoxeneb.pdfIn PDF document text
    • http://zenkatsu.dk/files/37016013587.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/4613848711.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/tofedawepasejanibokuz.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_off0000b6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6CD 10780 bytes
SHA-256: 23b2249d84bc6aee7e6a863a1cd1e267612929f6b529c7fc1bc946b9672e0c7c
font_01_sfnt_off0000cf5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5F 16980 bytes
SHA-256: a85afe49b9d2384c15573267e67f371b03315b3f57984af60f054f7d42c63165
font_02_sfnt_off0000fadc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFADC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1