Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa30b8ff53726e9d…

MALICIOUS

PDF

85.3 KB Created: 2021-09-19 02:34:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: cd48aadf8fc1403cda9ccbce33876ee3 SHA-1: 3f8dccdf0c0dd32b4f8f53f74267bc2a35c3775e SHA-256: aa30b8ff53726e9d0aba10d5e8959555653e795a470b12de812525d6e5d01536
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, several of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and a link farm heuristic suggests an attempt to direct users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://linker.tw/files/rupigegorijegitupexigule.pdf In PDF document text
    • http://ave-france.com/pics/files/nenuwiposuzozozoxo.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/1235326232.pdfIn PDF document text
    • https://siriusdynamics.com/assets/uploads/files/86463274352.pdfIn PDF document text
    • http://daeryuhealthcare.com/ckupload/files/60281974389.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161430428b25d8---34723905310.pdfIn PDF document text
    • http://nicolalazzarotto.com/userfiles/files/35402358849.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/58059347265.pdfIn PDF document text
    • http://hyundainhapkhau.net/upload/files/69373485804.pdfIn PDF document text
    • http://rayanchem.com/d/files/titepepaka.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16136762c3634a---99648805017.pdfIn PDF document text
    • http://kayapaliinsaat.net/file/25642188812.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210913121321_1547902129.pdfIn PDF document text
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/femajokig.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/rufutixuvivoru.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614660e1708d8---legujosasif.pdfIn PDF document text
    • https://altonika.pro/files/fck/file/72663052717.pdfIn PDF document text
    • http://bige.vn/uploads/userfiles/file/nimiz.pdfIn PDF document text
    • http://3dtechgroup.com/uploads/image/files/nokopusubadofewavijo.pdfIn PDF document text
    • https://nbtele.com/en/cache/fck_files/file/78265812767.pdfIn PDF document text
    • http://jtg-antracyt.pl/files/file/puperezevos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=android+slideshow+appsPDF 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_off0000eb8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB8E 10456 bytes
SHA-256: 7c5bc7808b5c69a24c6468ca90fd0bb717b9c3df6dedd07c812b9f90e3979a30
font_01_sfnt_off00010345.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10345 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B57 17180 bytes
SHA-256: 60743e10f562ca9fab57a7bf68ddbac67c9b68cb1a3cafcecad0d896830529ab