Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8781cebc997ac43…

MALICIOUS

PDF

85.9 KB Created: 2021-07-15 12:15:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4e534cb0e8f7f1ec5ee069d3db22fdd SHA-1: 375a3eba9404ec2de8570336eb6d74d7f1f7714d SHA-256: c8781cebc997ac43dcef5a2725663e7b9a81ab1ebfd104f23654a70c65392635
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, so the analysis relies on the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://baglab.pl/galeria/file/33480383507.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/map78e7b7epfe723ucjfd89vei/21168884262.pdf
    • http://samrayburnclassof1980reunion.com/clients/873185/File/sekajupapimopebogenig.pdf
    • http://broadmoor79.com/clients/864886/File/30646459380.pdf
    • http://newgatedesign.com/Images_upload/files/92091708467.pdf
    • http://asfus.net/virgsurv/userfiles/file/42625697990.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a0259ee73f---lemoku.pdf
    • https://vleek.com/uploads/files/topaguputanezaj.pdf
    • http://yuha.be/_files/file/36934916500.pdf
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607069aed3d3e---namutamusate.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160c5660e19d83---61176376583.pdf
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db10b65008e---89448729305.pdf
    • http://n2nlah.org/UserFiles/file/75218301602.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e5bfe03db11.pdf
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/gutas.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/b3f4719ccdcf5ef20e0a81dae6efc98a/43859226009.pdf
    • http://scbczy.cn/up_files/file/20210602_105447.pdf
    • http://cn-noah.com/uploadfile/file/kexelimigogol.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a5bcd4a196---85634576562.pdf
    • http://chinasoftcore.com/userfiles/file///mafiwemevubefilat.pdf
    • https://cakesandcupcakes.net/userfiles/files/widupudararufasux.pdf
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/kost18vkp3noe1t58bgff43l11/murolusulufexoxisobo.pdf
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/280f29d11378a5fe6b087f8b386c12ad/nikew.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=after+2+full+movie+online+sa+prevodom
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed2b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED2B 16792 bytes
font_01_sfnt_off00010542.bin
9b3ac4b8c3a6529dba50f5124a58f5308d51ba0508222d3a91e3a0a47f3495d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x10542 10924 bytes
font_02_sfnt_off00011ea7.bin
520e06c2957eefdb183e78c1ca30b73e26e12ae05badac4e5a1cf4521a19e757
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA7 16872 bytes