Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1cd98c5be2ff55e…

MALICIOUS

PDF

97.2 KB Created: 2021-08-14 17:20:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 78e136b98ea6e1226dbdc4ba60da66e8 SHA-1: f2347ae90d5f64faf113795d7558e1ebe0ad201b SHA-256: a1cd98c5be2ff55ef01c395ac1a80e902eb26ad65577c116c16329a085387447
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or SEO poisoning attack. The document body was unreadable, but the presence of numerous external links and the overall structure strongly indicate a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://anhbanglaw.com/userfiles/file/57140359668.pdf In PDF document text
    • http://thanuyentea.com/ckfinder/userfiles/files/kulazisovafepoji.pdfIn PDF document text
    • http://ajk-opakowania.eu/upload/fck/file/vizuxozabetodob.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/8edc3783b014fd80468a787de903109d/74841317203.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/24705332520.pdfIn PDF document text
    • http://mahkotacare.com/tmr/userfiles/files/68899299094.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/fejexezawibapiza.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/4468335437.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///20210720184656_863329173.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfa3a5841c---katiniw.pdfIn PDF document text
    • https://vestol.bg/files/file/daweri.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/78156639902.pdfIn PDF document text
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/056f74nns3j4g1j4n8btpbeahr/49824109836.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c6f22915c4---27298348113.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e49322644df---39212435447.pdfIn PDF document text
    • https://elektrona.cz/files/file/22583117497.pdfIn PDF document text
    • http://digifast.cz/userfiles/87016446020.pdfIn PDF document text
    • http://juentai.com/userfiles/files/vubibim.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/dufixalegusebozosa.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160735602ebcbf---4993657813.pdfIn PDF document text
    • http://www.musicboxpiano.com/contentfiles/43669534462.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/4c804bebbfa55eb01bf9395beb4b6110/bosoferamesopokolobipi.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/12487226000.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/zakebesememaxiwokodural.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=coreldraw+graphics+suite+x6+free+download+full+version+with+crackPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ff06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF06 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001171d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1171D 11544 bytes
SHA-256: f4656bbe8b33b75e8714d76ec4dd84d60e2e087b60ad1a91567b475bf135a4f6
font_02_sfnt_off00013261.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13261 21548 bytes
SHA-256: 464fd4848a16751bb746188c6fbeab311cc289cadf944b6f039bd1713abccad9
font_03_sfnt_off000169aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x169AA 2640 bytes
SHA-256: 5f125c68077b23685eb6e2bda4d666969c1d47bd48e0dbc29202517ec675116a