Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fd77bd7e1d690ac…

MALICIOUS

PDF

67.9 KB Created: 2021-05-25 17:10:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: eadef1e16b0d7711589abdb9013e1fff SHA-1: b47c4073e1b47f4f5b9369f2f5b5623b4a681424 SHA-256: 1fd77bd7e1d690acee6bb980842c3a4ba2ef0545b7ea185480f224b2cb33a16a
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are identified as compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to download further malicious content. The document body, though heavily obfuscated, appears to be a lure related to chemistry review questions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/565ab4coo4apdq2u7iqc0t02u8/64583680648.pdf In PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/jai6b83sa0fgssu8bvb5872qr7/8015808707.pdfIn PDF document text
    • http://refta-bg.com/userfiles/file/55211123598.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160838e97db734---93849388030.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/tamiwokukerufedef.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1606c937b47368---jaruzerikapo.pdfIn PDF document text
    • https://www.swissfillon.com/wp-content/plugins/super-forms/uploads/php/files/e0d2288cd2b67e94d99987434a966586/fevitoxiju.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16078ca519ed06---roxoziju.pdfIn PDF document text
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077d3a09bf84---nodawubitavaxejirutitotu.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b22161e92b---905869516.pdfIn PDF document text
    • http://karthikeyanjayaram.com/userfiles/file/zetozijurozugawu.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/98ebe3265ca03c87a1039eb868d1635f/zilagukekagudapubijija.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/8rtv4v97dd08pk641dudtiquq1/kinurutez.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a06b198dac8---kibisederodoge.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/21324659696.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/9922f521f73c9d2d81e54145db96cf6b/72399137118.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=chapter+2+chemistry+review+questions+answersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d19b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD19B 5556 bytes
SHA-256: 78353c472703c4691e2724bd920d3af70f194dc0a42e22fbccaaedf2a4d2548e
font_01_sfnt_off0000e470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE470 10056 bytes
SHA-256: df1f60aaa5b907d79454c533018c355ead183361a961ad9150c6ae6d0aaeb388