Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa81ea557d21e6c4…

MALICIOUS

PDF

83.6 KB Created: 2021-09-05 06:51:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 50cd7c4296f6153ebbe19d08228a96c0 SHA-1: 350f462ef27a207f57a71ce70806804db99abc42 SHA-256: aa81ea557d21e6c403357ae3b3c777736e79763c8023900fe82a0c2267b14905
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to redirect users to malicious content. The PDF structure and embedded URLs point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://oniceh.ru/uplcv?utm_term=drenaje+linfatico+manual+para+embarazadas PDF link annotation
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16130900b0e0a6---wusuzusibavosimefubir.pdfIn PDF document text
    • http://fullx.net/files/rikuseledolikubivivalon.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac0c43ba5bc---dolexexipepeneziwed.pdfIn PDF document text
    • http://myapartment.de/web/editor/files/dizejezidesiputufinajip.pdfIn PDF document text
    • https://mps-india.com/userfiles/files/76933204028.pdfIn PDF document text
    • https://zlato-stribro-investice.com/upload/files/67751553448.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16102568e546c1---91748729977.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210610033133.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/vd86ck0thft8pr8nuv9ln1ub7u/xizetojedirifavejififol.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7ba138876---5240082646.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160794a7d0bced---71857544129.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084cfad44c04---77867526465.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/d562d2954ab5d3a5a8713c1eb64d17ee/lowefovagevepudatu.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-7-28/20210728055148217308.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/toeqjbcg3sn61i9h1s763rb6e2/depefekufo.pdfIn PDF document text
    • http://xn--eyt274i.com/upload/files/7476083555.pdfIn PDF document text
    • http://cunningham-reunion.com/clients/7/73/7399477c88ef979e1ad3ac38e42cffcc/File/89545468904.pdfIn PDF document text
    • http://suspensionestg.mx/userfiles/file/vupumivisa.pdfIn PDF document text
    • https://kovtec.pl/eurostyl/photos/file/82881494262.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/69794095639.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/88742072071.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e0ef561a5b6---piruxiluromodew.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/d8e7d06dc3e4a133cbc1fe3184b455ca/45141620258.pdfIn PDF document text
    • http://winteringlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lojetomulokibu.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/d367fb24a4519f243261b349ea0c23e5/97306793801.pdfIn PDF document text
    • https://dallaslandscapedesign.com/media/files/mumelunevaxuvukivis.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_off0000dd3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD3D 18844 bytes
SHA-256: f92b30d84bef705146752f1ed555899b9bd139d5760040987a41f217d89d3a4c
font_01_sfnt_off00010cbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBE 11212 bytes
SHA-256: 4ef087255f45140087a3ee5be2c954dc8934dccd79cf60f18eaa012c5f905e5a
font_02_sfnt_off000126bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1