Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c424a9c5c94fc32…

MALICIOUS

PDF

76.6 KB Created: 2021-09-09 11:49:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3ba56fd2c754bfe422999c29ced551c6 SHA-1: fb2815b28009b4708270598979a47be9c377f078 SHA-256: 7c424a9c5c94fc32cb5c5acd1e053c61003327b78543ea6addf794b691de7193
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple compromised websites, some of which are WordPress uploads. The primary URL points to a download lure for an APK file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://synerhu.ru/uplcv?utm_term=sonic+pocket+adventure+apk+download PDF link annotation
    • http://mgbig.com/upload_fck/file/2021-9-7/20210907140551743964.pdfIn PDF document text
    • http://detskaoptika.cz/ckfinder/userfiles/files/71983877801.pdfIn PDF document text
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/66549696235.pdfIn PDF document text
    • http://sakra.sk/storage/file/3401991002.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/turofepav.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea8160eda5---99398053007.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/cf6b8b18444b788b0abb4ee5d2df00ea/76139043274.pdfIn PDF document text
    • https://emailing-online.fr/uploads/userfiles/file/45564398736.pdfIn PDF document text
    • http://packagingandfoodmachinary.com/userfiles/file/48127891894.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16136d58092517---80618105311.pdfIn PDF document text
    • https://digireg.lu/upload/32021312258.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/mosofudasixojufe.pdfIn PDF document text
    • http://adamslakeband.org/userfiles/file/72467480108.pdfIn PDF document text
    • http://yjbiotech.cn/upload/files/golakorega.pdfIn PDF document text
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/8831860349.pdfIn PDF document text
    • http://topoint.net/userfiles/fckFile/20210903144811.pdfIn PDF document text
    • https://trungtammatnamviet.vn/upload/files/dolufalunami.pdfIn PDF document text
    • http://cppzone.ru/users/blogs/file/1209077197.pdfIn PDF document text
    • http://tiquital.com/documentos/file/notefilelakozug.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/c88c4708c973bc7766d5643616a2e320/pafufiliguvarutuxikujakad.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16135760268973---86842906154.pdfIn PDF document text
    • https://china-glass-mosaic.vegner.com/userfiles/files/20210902_040140.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/0rqin9r6gsmk0ipp923rfsnh21/walatevosefolokuzanajatet.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_off0000c567.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC567 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7E 10760 bytes
SHA-256: 709225eec0651d50eb54d038cd4c2b5c8332ee7d39d5ee03adb1adb29e0bcec7
font_02_sfnt_off0000f66c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66C 17988 bytes
SHA-256: fcc43208bafe13d02381448451810ab165056048eaa811db30e2786d5db626c9