Malicious PDF — malware analysis report

Static analysis result for SHA-256 f311dd33ff1fcb5a…

MALICIOUS

PDF

87.7 KB Created: 2021-07-16 10:46:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: b6e67fcea35f695c86affea532173c39 SHA-1: fe6f2a27c920b18f37f0dc33ba7eb924c814c6a0 SHA-256: f311dd33ff1fcb5a14d408248b10b033f73f8a0b3f242f25ed4fee71c7574393
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress installations and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The primary function appears to be acting as a link farm to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/dcotb8of4488mrdk58co61o5vd/kuzudoxofan.pdf In PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a61bc47ba62---88680055921.pdfIn PDF document text
    • https://roc.mn/uploads/files/69858008406.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/90959857244.pdfIn PDF document text
    • http://csc0516.com/userfiles/file/20210703132315_fkchxc.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099b84a16475---mekagisesulawotemikuvi.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160eca981ee223---refufobenisen.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160743310365e7---16410595472.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/zugop.pdfIn PDF document text
    • http://susasoft.com/upload/userfiles/files/54555501863.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16075fa8de84b4---dotulesuva.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160942a9da1fc3---94496647342.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/16458309448.pdfIn PDF document text
    • http://bahtiyardishekimi.com/fckfiles/file/47790058945.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/f13eb635353195e5164d2f203bff6f44/xoleribuza.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/kugif.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609edabd56531---89598915751.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160de217996de8---83415772435.pdfIn PDF document text
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16095cf0ec2fe7---kowuluwofikenisuzirise.pdfIn PDF document text
    • http://testplanet.nl/uploads/files/gedosipifowudowes.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607723f1a7b37---malaridavibetemoriba.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/468f21c014ca620e6846b0d03f9bee1f/24375030250.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608ec9f09f7ef---72922092837.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce271977e1---45255342326.pdfIn PDF document text
    • http://sdds.be/userfiles/file/12640162624.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d5c2ea703d---24611304591.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=longest+common+subsequence+time+complexityPDF 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_off0000ef0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0B 11012 bytes
SHA-256: 04ff886cf0430047b7d1e31874d052281551629df848f1519813f161710a406b
font_01_sfnt_off0001082b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1082B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001203d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1203D 17788 bytes
SHA-256: 2b2e3ed47c37f5fabf2c8a29941b1078cdb193c92f45c1efc2cafb7a0ffb750f