Malicious PDF — malware analysis report

Static analysis result for SHA-256 37d18aacc78e1895…

MALICIOUS

PDF

70.2 KB Created: 2021-09-16 23:12:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c988cf88aff551ca9d686fd56a4d1aa6 SHA-1: 380ad938ff050428a19b4c4eda022da09e0cea2d SHA-256: 37d18aacc78e189539d91b22a64edf66d728390e263982de0ca1536f58bd3cda
156 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs and link farms pointing to various domains, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://smidgel.ru/uplcv?utm_term=five+examples+of+collective+noun PDF link annotation
    • http://digilit.ir/basefile/digilitir/files/liwukilu.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631359105.pdfIn PDF document text
    • http://hyunshin.net/userfiles/file/figinirudofagegivepinok.pdfIn PDF document text
    • https://conexkarvan.com/cache/fck_files/file/zasixutabofisepojo.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613986d57856f---fakisowerafimoxefidijegi.pdfIn PDF document text
    • http://bora.su/ckfinder/userfiles/files/8467719399.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2120e8d87---19864867654.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/37734492823.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/27937977799.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/tupulofa.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/buzenovupezesonikum.pdfIn PDF document text
    • http://salamatekhanevadeh.ir/ckeditor/files/files/gewalezalofukipi.pdfIn PDF document text
    • http://techmechengineers.com/uploads/mefewodejenefejavel.pdfIn PDF document text
    • http://naturalwonders.com/uploads/files/xuwazenutarerog.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/f9ac5b86955e27606fea06ea9010d20c/47560810904.pdfIn PDF document text
    • http://wsm.hk/images/files/gatoxotinufuxuj.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/19595650464.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/14858694294.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/fukepem.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/53105221722.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/nalariwegukoraxemiwofot.pdfIn PDF document text
    • http://huh.hu/UserFiles/File/lelutidevorugujebudajojov.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_off0000b4a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4A1 10788 bytes
SHA-256: 399128c6fc23c33682f98cfee049bee818531b9f9d5a91fff5dcba17f71e99e3
font_01_sfnt_off0000cd85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD85 14964 bytes
SHA-256: 007eed19838c77fe4cc6d78c07924e49072da908388de28854d03d0377ca9ead
font_02_sfnt_off0000f2f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1