Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa31acb1a967b647…

MALICIOUS

PDF

96.9 KB Created: 2021-06-28 04:23:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 06e6b9c38ea01201db0568864d7282ef SHA-1: 0843a0ee2d7b42dec273450de079fd0c49106d11 SHA-256: fa31acb1a967b64717a4c8d1c72920e77314e5f15cc6a0fa4fea80a159e7dd19
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest this document is part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://smidgel.ru/uplcv?utm_term=apology+for+missing+a+meeting PDF link annotation
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/kh1hot2pgof2i8feam3vqomhin/29896149069.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/u61bm2jv1f4vci8va9ibc1t1l5/nelavolegififasip.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/27166941f07a60076178e40a166c4cb6/welunadap.pdfIn PDF document text
    • http://matsonconstruction.net/userfiles/file/72575206453.pdfIn PDF document text
    • http://www.look4job.gr/images/_user_na/file/33519546402.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/b4e553184e871d0435657d5101f6d8ea/rofupegiz.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087e2ef92693---pemakatovutev.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/fde468403e6280c98329e54d449b50f8/puxobipojodew.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ac4d0c6a724---32478693005.pdfIn PDF document text
    • https://bem-sa.com/img/file/33854467968.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/93033665131.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/vimusinejubanigedubagusu.pdfIn PDF document text
    • https://mariapolis.net/ckfinder/userfiles/files/guzomudaloduka.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/92418005546.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/b85e7885a960d155491b135bfba1e380/jusixesobur.pdfIn PDF document text
    • http://bundoreh.com/fckeditor/files/file/45473024128.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/ioeoi23mn803iltqlkboja77v7/51129154865.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/vuwikupunuv.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a500e8aa55b---vabepudewekige.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16077cdee09618---94839908442.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/98edd431e150a0aba35a04e7677b7366/pekavesid.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/repegowabijilibuxuzija.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/10871857072.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/8qvph2u5fa6i93hk4slgi6l935/webukorafobufexapigoxifaz.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aca366aaed2---48315109278.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_off0001184b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1184B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001305d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1305D 17232 bytes
SHA-256: 0635a9649004ce40ea01499ddf3c8270ee2ba725dccf5fd13b1c5b241bcaaae4
font_02_sfnt_off00015d7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D7A 10796 bytes
SHA-256: c3e193673c4c5df2ae8eb342d4b771a6c7d55a0146ba495db91db47f9dbac846