Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3f767f265beaeba…

MALICIOUS

PDF

78.0 KB Created: 2021-09-15 18:35:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7377e0b127d75e6eb986bb854ea5f2f1 SHA-1: 195863725049456379d3df2c2960e3ebb9b72663 SHA-256: a3f767f265beaebaada1a1557dd48ef4aba7f8156b3eebc6b9f17cb7f95249eb
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm hosted on compromised WordPress sites, with multiple URLs pointing to potentially malicious content. Although no scripts were extracted, the presence of external URIs and the nature of the heuristics suggest an attempt to redirect users to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/8327ae3227501976d9bf50024717b4f1/subomag.pdf In PDF document text
    • http://thuonghieutoancau.vn/uploads/files/zilesaparovopudojuxix.pdfIn PDF document text
    • http://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/85113889859.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411a3f83ed0---96369451616.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/8217830503.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/80972023490.pdfIn PDF document text
    • http://tottazo.com/userfiles/file/rinomexog.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/85901001777.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/3413956883.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/zojutaj.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/xiparepetotep.pdfIn PDF document text
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/tajilurut.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/85310124074.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/mokejowanipevelexuduniv.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/8327043614.pdfIn PDF document text
    • http://theurbanbazzaar.com/userfiles/file/91739931754.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/50602628291.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/firaxuranegesikoxes.pdfIn PDF document text
    • http://gmart-express.com/demo/uploadpic/file/rakaputog.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.org/upload/files/duzamawoduderenilab.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/21055923229.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16139468784123---rexotewikedewuj.pdfIn PDF document text
    • https://agmatbaa.com/upload/files/felukax.pdfIn PDF document text
    • https://conexus-study-abroad-travel.com/ckfinder/userfiles/file/tibanefunosenozeni.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=hill+club+racing+mod+apkPDF 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_off0000cc16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC16 17740 bytes
SHA-256: 27aa4c8f6f86546f16b2c4174c4a4d55431bd326f0ff24981fd6a6e2b0899a30
font_01_sfnt_off0000f9ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011204.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11204 10780 bytes
SHA-256: da962ed832c44f0aa204aec53641c10366bb4fcbcaa32321c6a63c059af599ef