Malicious PDF — malware analysis report

Static analysis result for SHA-256 a899a287c93d0ad4…

MALICIOUS

PDF

90.3 KB Created: 2021-06-25 22:23:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 80baf86f344d5a65093cc7548ab48090 SHA-1: b8cb2a862a375261fd6fe515b1c29e65bb96ca8e SHA-256: a899a287c93d0ad42558770e0faaeb258fabeb0d166fe58c8596ab9e35dcfda6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to external sites, many hosted on compromised CMS upload directories or disposable domains. The document body is unreadable, but the presence of multiple external links suggests an attempt to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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 http://au-zlato.sk/upload/files/77585047909.pdf In PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9b6e83382---posulija.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/46f313e86e874c27d50245c04b208ee1/moladopefimepoke.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16077d42648924---gitevoporuwet.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d0a291092---pexit.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16080ad9294a86---vesusiju.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/b89e8e94a86c63036e0a7b1bf09d6b58/jukawos.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/34979c8053c1f8064485d829e1b03e11/vaxuxawotixi.pdfIn PDF document text
    • https://sahodayabbsr.com/test/fckeditor/file/83307237173.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/xifuzowusifitubodipizowa.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16071e16012290---gisujidobelorexi.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/160bec18103919---fuwutamizaxejumitibo.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/togifu.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f66e989e6---jevajeni.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/5003723720.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087d1d4ea53c---60843614497.pdfIn PDF document text
    • http://leadershipcareer.kr/fckeditor/_upload/file/safavuxoputafujo.pdfIn PDF document text
    • https://edcasys.com/ci/userfiles/files/36228640119.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/e5p0h727qvl2v6f2vj49eegkcf/sosufuvusoragavarokema.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/0q09mol3q5ftbc0ndg913kd6pp/82164053850.pdfIn PDF document text
    • http://caramelitos.sk/files/67472035840.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/77885f8b832a3321125f481d48f4fe9b/8295910431.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac885186bbe---tizojela.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ab76b0a23---mupefofewevi.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/e51541fb9640bf880aaa16ab8cfd776d/woputojoxatozosapud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=why+does+my+dog+bark+at+the+wallPDF 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_off0000fede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEDE 16988 bytes
SHA-256: b5fc84907c71b51e909f09395c2294520a1514d4ecb412d2e53f0e82aecce558
font_01_sfnt_off00012ac2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AC2 10924 bytes
SHA-256: cee9211378161f3ebdb97e7fb3df91ed60ed41be116207e40a297f7e4bafc176
font_02_sfnt_off000143fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1