Malicious PDF — malware analysis report

Static analysis result for SHA-256 86877d8b4686ba8f…

MALICIOUS

PDF

68.7 KB Created: 2021-10-01 05:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a92c0c4285ec4aa116f75426a9b47b61 SHA-1: b256544c5e99a6b974058249a845814417b81272 SHA-256: 86877d8b4686ba8f910a3667c8f790ea899d99852fa5aea6443d3622d1951d0d
156 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on multiple disposable domains, a common tactic for phishing and malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing unwanted software. No scripts were extracted, and the document body was unreadable, but the presence of numerous links to potentially compromised or disposable hosting services is a clear indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/e658ddd7436e79ea5609e2994453cf85/80323060721.pdf In PDF document text
    • http://gro-felix.si/uploads/21084706273.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f00803d9cc---72821907429.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e363244245---43620465200.pdfIn PDF document text
    • https://preciseenergygroup.com/media/vededogaxes.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/79013302152.pdfIn PDF document text
    • https://htapigroup3.com/contents/files/feluvijutasotosexamosem.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/rodipejepanisekimoke.pdfIn PDF document text
    • http://studionegrelli.it/userfiles/files/lofunaw.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/42149420112.pdfIn PDF document text
    • https://emtracing.net/userfiles/file/balapuxil.pdfIn PDF document text
    • https://undergroundtakeout.com/userfiles/file/fisuxidur.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613864436bb08---81872656937.pdfIn PDF document text
    • https://schmitz.cz/res/file/56726207910.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-13/20210913170547430520.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/vigadipefekomakinexiteb.pdfIn PDF document text
    • https://xtremefitksa.com/ckfinder/userfiles/files/89963330514.pdfIn PDF document text
    • https://wrd13.com/force/file/kifofuxipudetuvatolefegiz.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210916_CAD3B9C787CFA39C.pdfIn PDF document text
    • http://theflowermaker.com/uploads/File/16402496678.pdfIn PDF document text
    • http://ngoinvest.com/uploads/ckfinder/files/38003765221.pdfIn PDF document text
    • https://fizjolech.pl/userfiles/file/42781093051.pdfIn PDF document text
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/koporabuzuvepebowu.pdfIn PDF document text
    • http://jcnjl.com/userfiles/files/nubelajidakikulanekuw.pdfIn PDF document text
    • http://oris-am.com/editor_up/4287578580.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=pubg+1.0+apk+downloadPDF 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_off0000b05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB05C 10636 bytes
SHA-256: a77550d8f30c950d34362fa8c0477ab609aecfee9b0daa0a9d1d94a6081c0943
font_01_sfnt_off0000c869.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC869 14684 bytes
SHA-256: 81def2967ae03c6e8b571917645c0c7021fd3ee69539ce621e6e16e26f8a351c
font_02_sfnt_off0000ed74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1