Malicious PDF — malware analysis report

Static analysis result for SHA-256 1753fa090eac5614…

MALICIOUS

PDF

93.3 KB Created: 2021-09-02 09:49:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a2ff778f21143a0d87e5f66d2fc39ebd SHA-1: eddadd523b1b4d9c388757e30c705e69c5015561 SHA-256: 1753fa090eac56142f274f8cbbd716ed427044cafa0a7be25c96ab3af244a032
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting sites. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 http://nasikampung.info/contents//files/duloninoxe.pdf In PDF document text
    • https://www.retake.dk/ckfinder/userfiles/files/78375530400.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/sudimotovoxarekonav.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/sotavepedamisunigino.pdfIn PDF document text
    • http://mosjob.ru/images/file/93272139498.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/89803069469.pdfIn PDF document text
    • http://inlovehuahin.com/file_media/file_image/file/betetijevowo.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/97114138524.pdfIn PDF document text
    • http://kaowei.tw/image/files/20210526_182351.pdfIn PDF document text
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/koxukege.pdfIn PDF document text
    • https://demetraproject.eu/ckfinder/userfiles/files/muguzebepuxo.pdfIn PDF document text
    • http://3bbb.fr/ckeditor/upload/files/rexazunanij.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b728bc94bf---34193192576.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b65bfb8b012---59378960966.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c5af56ae8---60562970162.pdfIn PDF document text
    • http://www.look4job.gr/images/_user_na/file/pesezabajodem.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16106a1171c5ac---vakixuzuwikopojojilito.pdfIn PDF document text
    • https://haidangpc.com/contents/files/bokatovegosudipux.pdfIn PDF document text
    • http://sivam.pl/files/file/91906347841.pdfIn PDF document text
    • http://master-br.ru/img/file/gexekozodurixiwodiras.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/66322613983.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d45d17bbde9---xisotojazo.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/d71a6dd4c659ae931092d4bf32eddd10/sesoka.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/pukaguranawox.pdfIn PDF document text
    • http://arebiatours.com/uploads/files/50199029777.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=cover+page+ppt+templatePDF 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_off000106e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E3 18268 bytes
SHA-256: f8f1f118cedd1f8d98bfe9c3c4afbccd849624982056d0a51cca4ad82ff0f414
font_01_sfnt_off00013696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13696 10328 bytes
SHA-256: fe5181f40a7a7d0aaba2b9c731856ea43c72e89b3b0bfffc77f7a2d35eacad06
font_02_sfnt_off00014dfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1