Malicious PDF — malware analysis report

Static analysis result for SHA-256 38e55ce7fe585044…

MALICIOUS

PDF

79.8 KB Created: 2021-09-19 19:02:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 35dcf82f101d5f43ae36578187aaf03b SHA-1: 2a62f2ae2c92ec23bc15ef64e1823642d8c88e9c SHA-256: 38e55ce7fe58504481064bdf3b5a4e34bc90d7bdcfd365a3d985dc7e09b663cf
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://peter-scherer.de/userfiles/file/28181624555.pdf In PDF document text
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/90491544419.pdfIn PDF document text
    • https://www.comperat-89.fr/ckfinder/userfiles/files/napazosu.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/somovukunexeriza.pdfIn PDF document text
    • http://maksimetall.ru/files/44066709608.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/zisibagazaxusa.pdfIn PDF document text
    • http://fcgo.tw/uploadpic/files/jozetorigif.pdfIn PDF document text
    • https://emilline.dk/ckfinder/userfiles/files/luwodajedutofasuxo.pdfIn PDF document text
    • http://fmmvn.net/userfiles/files/pulomemusekedebevukile.pdfIn PDF document text
    • https://estatecambodia.com/htdocs/cljr/data/files/fodujezu.pdfIn PDF document text
    • http://cybernet.asia/UserFiles/File/rokufojevepenoperofiripak.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/78352730976.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d93a0bceb---21253300215.pdfIn PDF document text
    • http://lecostationery.com/files/file/88443143300.pdfIn PDF document text
    • http://chuabenhxuongkhop24h.com/images/files/65495919533.pdfIn PDF document text
    • http://turksebruiloften.nl/userfiles/file/60186208151.pdfIn PDF document text
    • http://tianlanlawyer.com/filespath/files/20210902092128.pdfIn PDF document text
    • http://tuderprogettazione.it/userfiles/files/41319040062.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/3071341852.pdfIn PDF document text
    • http://novelinternationalschool.com/ckfinder/userfiles/files/pakedujuvazakipazuvedirew.pdfIn PDF document text
    • https://vildmarksjagt.dk/userfiles/file/71983640336.pdfIn PDF document text
    • http://motolargo.pl/userfiles/file/24014081378.pdfIn PDF document text
    • http://thriftstorewebsites.net/flash/thriftstorewebsites.net/file/33784776475.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/qemett7bjpb1ciklakv7m5ids4/xebubodiwexu.pdfIn PDF document text
    • https://dcoderesearch.com/uploads/vozisepadefexopoved.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/161459afe34f01---gebajibakoxuwaxiledinip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=nature+sky+background+hdPDF link annotation
    • 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_off0000d2c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2C6 10936 bytes
SHA-256: ce4649bc7a1e40667f0abeb62cb29544ba5cf20df32b9f919d879399b2b8c1cf
font_01_sfnt_off0000ebf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF4 17188 bytes
SHA-256: 548324711176d81894814cdd28d4e6bec9f9fc5d8627d7668f9586c1cd20cc59
font_02_sfnt_off00011805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11805 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1