Malicious PDF — malware analysis report

Static analysis result for SHA-256 8875c3c99c3c9380…

MALICIOUS

PDF

85.1 KB Created: 2021-09-02 02:24:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: dd5bffccf5925486ee3ae7a88df779ff SHA-1: 425c6f0256e56057689246b646aa8ecb3bc0a24e SHA-256: 8875c3c99c3c9380325a74eb7bdcada56e1237078300d5ab2742ddae7b1795bd
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

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://muratay.nl/userfiles/file/89251426383.pdf In PDF document text
    • http://colorfusion.us/admin/images/file/22008485684.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160892a07d0692---revovodezelomiwi.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/75jrpctmr1l2ov1abfmuub98cl/waful.pdfIn PDF document text
    • http://shopcode.ru/uploads/file/vurajunalubexinim.pdfIn PDF document text
    • http://daiichibus.vn/uploads/news_file/228380044.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/4611307075.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609d173042a87---20335563103.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/69613942117.pdfIn PDF document text
    • http://tochuchoinghi.org/files/12848356449.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084daf253c87---zapevoxorifudemujefet.pdfIn PDF document text
    • http://standardamulet.com/files/files/29790193635.pdfIn PDF document text
    • https://craft-personal.de/userfiles/file/79301941051.pdfIn PDF document text
    • https://cafe-malaysia.com/contents/file/xamiliboxesiwomidije.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/aab7fbee3fc42c45daeb92cf93f4b358/sefezupupuja.pdfIn PDF document text
    • https://greenvalleykerala.com/ckfinder/userfiles/files/dokewa.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9e2f43590---zizideworezaneburituradon.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/potililebixotexakanibas.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1626191545.pdfIn PDF document text
    • http://harlit.com/upfiles/file/bibes.pdfIn PDF document text
    • https://0286869143.com/editor_images/files/20981030596.pdfIn PDF document text
    • http://twtipa.com/upfile/files/2021/06/23/20646766382.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/166e85278813508760bb1ba75d53019c/41899006831.pdfIn PDF document text
    • https://norservis.cz/files/files/98903349609.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/9297299889.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=intensive+care+first+aidPDF 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_off0000e4bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fccf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCCF 19504 bytes
SHA-256: 2bf3c270f4f40e808613f68d580b127b0fa4bafd7e7752f5ab1274c49bbbafbf
font_02_sfnt_off00012e78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E78 10320 bytes
SHA-256: 987eeb93d5529fca41d52ecc0e7429c0ba0adbd761139b143ae37744f348d680