Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4332abb691d09b0…

MALICIOUS

PDF

83.8 KB Created: 2021-09-21 04:32:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8ced3723c47e6362f3397897edb8422e SHA-1: e19eec2ec0057bc2ddfdcb233f3361c92920dd6d SHA-256: c4332abb691d09b0689dd8e190bb911caf100f6787faa6e8ffd9a664d423be9b
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The embedded URLs and link farm heuristics indicate an attempt to direct users to external sites, likely for malware distribution or phishing. The presence of multiple compromised CMS upload links further supports the malicious intent.

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://synerhu.ru/uplcv?utm_term=download+zombie+catcher+mod+apk PDF link annotation
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1614762003663d---wotijixawova.pdfIn PDF document text
    • http://sghr.ca/upload/ckfinder/files/doliberatenipopadel.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/81220616790.pdfIn PDF document text
    • https://goodline.by/userfiles/file/3944615689.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613772bbbd314---tuwezobobojaxagusebe.pdfIn PDF document text
    • http://nessium.fr/userfiles/file/kinerut.pdfIn PDF document text
    • http://boldogelet.hu/media/jebowafazemibareta.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/vixibenozusazura.pdfIn PDF document text
    • http://letnipohar.cz/upload/file/budejugodozefotixokim.pdfIn PDF document text
    • http://satyavnetworks.com/fck_upload_images/file/81567261645.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/jezesobekitojawopewimefil.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/12850588319.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/84718000921.pdfIn PDF document text
    • http://prestinoequitacion.com/imagenes/upload/files/25554771323.pdfIn PDF document text
    • http://bainihu.com/upfiles/editor/files/16132391948.pdfIn PDF document text
    • https://patc.fr/imagesfile/17863805080.pdfIn PDF document text
    • http://terryloops.com/E/file/63586587848.pdfIn PDF document text
    • http://nghieuphong.com/upload/files/vutadexidogojaku.pdfIn PDF document text
    • http://leeclinic.kr/userData/board/file/mijuvokulipemevojigaxelo.pdfIn PDF document text
    • http://addisonplaza.abwingsmd.com/uploads/files/xowodewowodot.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613395bca4dca---zosatapawubikemitumen.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/joveromado.pdfIn PDF document text
    • https://aluvioneschicamocha.sinecsas.com/ckfinder/userfiles/files/38268504120.pdfIn PDF document text
    • https://marblobath.com/app/webroot/img/files/22590153620.pdfIn PDF document text
    • http://soundspace.eu/Upload/file/94164264194.pdfIn PDF document text
    • http://ciccioinpentola.com/userfiles/files/tiditewim.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_off0000e371.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE371 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB88 10992 bytes
SHA-256: ec6dc4194349efecde635fd0d4f1934bafb26c9acf413b11373326df2da50d9a
font_02_sfnt_off000114a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114A7 17140 bytes
SHA-256: 320d2d0cedf85ba22f65e23a144502b54ca98ca74e79a7d72c1dc7b99db73bd8