Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5160b06a010b0fc…

MALICIOUS

PDF

77.2 KB Created: 2021-09-09 11:30:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 13a6109fe98bde6ca9fbe5ec00c7eea6 SHA-1: b21fff94dabda34ea7f4309725a16d2958bb2970 SHA-256: b5160b06a010b0fcd5a6b42f44d1deb8910eba64b73d4ed3b21454e32a04e103
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on compromised CMS upload directories or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous URLs point towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://infrive.ru/uplcv?utm_term=chaos+dwarf+army+book+pdf PDF link annotation
    • https://kawanmto.net/contents/files/kumezu.pdfIn PDF document text
    • https://peiitw.com/Upload/ckeditor/files/ririkodif.pdfIn PDF document text
    • http://onfireinteriors.com/userfiles/gabidupuxebegase.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139680179b7d---regegoveniwowoje.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161393d97f3bde---seloxutorimivod.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369f356776c---lalidulilupigiwesola.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/wamuvobox.pdfIn PDF document text
    • https://www.q-jin.ne.jp/ckfinder/userfiles/files/35312886581.pdfIn PDF document text
    • http://ky-auto.com/uploadfile/files/71008650987.pdfIn PDF document text
    • http://wjcopy.com/upload/files/dujipevotup.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/gilenipanugowokajijida.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/zovewele.pdfIn PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/memukipumifiratimurumikij.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///desubanukakesotu.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/napofojudajipa.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/81414785301.pdfIn PDF document text
    • http://ppfi-online.com/userfiles/file/13120894323.pdfIn PDF document text
    • http://hoanhaochemical.com/uploads/files/32266433385.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613508dd1f56a---kunuwureje.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/lawed.pdfIn PDF document text
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/52212265234.pdfIn PDF document text
    • https://camgloberealtor.com/userfiles/file/75381272007.pdfIn PDF document text
    • http://zhatuogz.com/uploadfile/file/96282457013.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_off0000cb36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB36 10756 bytes
SHA-256: 5052a42ac2b1c4ae85cf2ccd7365439556d5f001c511e26c1657f86a7a5c4b72
font_01_sfnt_off0000e3d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fbe5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE5 16768 bytes
SHA-256: 007a459e0a0f1fd4127cee8c1162cc827219e7c5f4ca62c58bd8935f0b8f8235