Malicious PDF — malware analysis report

Static analysis result for SHA-256 a571efccfcd7cba4…

MALICIOUS

PDF

76.3 KB Created: 2021-09-06 19:46:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: bee88ddc21a7a618edfc734902e865dc SHA-1: e4771d7bdb89e0c95a29f1f4b2dd6937faa45f75 SHA-256: a571efccfcd7cba49849f6cda9d603924232c889a3b09b279ac189f3b13b513c
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Some of these links point to compromised CMS uploads or disposable hosting, suggesting a malicious intent to redirect users to potentially harmful sites. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://gz-theoutfit.com/UploadFiles/FCKeditor/20210902072154.pdf In PDF document text
    • http://darec.sk/files/files/53434723411.pdfIn PDF document text
    • https://negaratoto.com/contents/files/wopigawonotibosafavep.pdfIn PDF document text
    • http://pogservice.ru/userfiles/file/walew.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b3359c8d05e---fipiniwumedajomugoje.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/c55dtrk5ktfd4aert7u2d9s2no/89304713482.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/b912ce3a1ef72aabe006e6b8743b2b04/87711993101.pdfIn PDF document text
    • http://xn--80aantfcaehjbxzf1m.xn--p1ai/userfiles/file/27050325097.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/dumotepusolodorabos.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/19893756936.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/89704069889.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/sipapevi.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/84674301687.pdfIn PDF document text
    • https://evermoral.hk/upload/file/1626664789.pdfIn PDF document text
    • http://hk-dcc.com/wp-content/plugins/super-forms/uploads/php/files/80k8bmfnt3f2kc87fskrbhr053/tutulofoz.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/34615863325.pdfIn PDF document text
    • https://tvsporedi.si/vsebina/87075131872.pdfIn PDF document text
    • https://abyway.lv/images/ck_images/files/93269176340.pdfIn PDF document text
    • http://brooklynsmokeshops.com/admin/images/file/disomijaxamowup.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c30fa169f71---zakoxewa.pdfIn PDF document text
    • https://taybaite.com/userfiles/file/zibuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=ifrs+13+fair+value+pdfPDF 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://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_off0000cca8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCA8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BA 16988 bytes
SHA-256: 27b7f82663599768979a19e36233f70b89902e8444c457980b86109d40390802
font_02_sfnt_off00011011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11011 10512 bytes
SHA-256: 99ff19c41e0da2d06c2deacb25e86b3a3dae602275502b665894f74db94f0b1e