Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a70b78cf845d746…

MALICIOUS

PDF

86.0 KB Created: 2021-09-18 06:28:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 88b6a9c34aa29a689967f4749d9fd51f SHA-1: 7bdb23d60362a5d1f328034774a76c2342b42fe8 SHA-256: 8a70b78cf845d746aca10b99af71420894f832606b9e49ca355acca5b409f502
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, and a high-confidence ML classifier and ClamAV detection indicate malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the URLs are part of a link farm, likely used for phishing or distributing further malware. The sample's creation application, wkhtmltopdf, is unusual for a malicious PDF, but the overall evidence points to a phishing or malware delivery scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://gniortho.com/files/Upload/file/gevazunupozotatafugizot.pdf In PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/60740510998.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/161316637d52e8---72902723558.pdfIn PDF document text
    • http://xn--9i1b14lzokxjcrti5um.com/upload/fckeditor/file/92974914694.pdfIn PDF document text
    • http://stylekd.ru/files/livovifo.pdfIn PDF document text
    • http://sameiroeventos.pt/ficheiros/keridipaj.pdfIn PDF document text
    • http://gediklimakinahidrolik.com/resimler/files/60743846432.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/bokenijefotugami.pdfIn PDF document text
    • http://kimkhimientrung.com/uploads/image/files/girafijew.pdfIn PDF document text
    • http://noithatsah.com/webroot/img/files/50390907398.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3c065f38c92fa080b535a6ed3927c7ff/vuxipoki.pdfIn PDF document text
    • http://tcihk.com/userfiles/lopufodolikixemapamoj.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/xosenetexokiremiro.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/jogelifelabifimiki.pdfIn PDF document text
    • https://dsverano.com/UserFiles/File/59703725115.pdfIn PDF document text
    • https://hilanguage-com-tw.triangle-design.com/files/siwadobetanodevopabonif.pdfIn PDF document text
    • http://www.biogreeno.com/cms/ckfinder/userfiles/files/55884023245.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/15134261267.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/pimoxasobafewenavetutupip.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/tuduvixude.pdfIn PDF document text
    • https://impeka.lt/components/com_mijoshop/opencart/image/data/files/puzamowegiwawab.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/xatewikenut.pdfIn PDF document text
    • http://becucci.it/userfiles/files/39497620624.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/5694177089.pdfIn PDF document text
    • http://etcpremium.com/userfiles/files/pepikabifezujebewarutasi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=architect+apps+androidPDF 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_off0000eb4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4B 10544 bytes
SHA-256: 05c17a3501aaee2b02a30e40bdcdeeae658989ed8e75d051c1aa8c644818aa3c
font_01_sfnt_off00010347.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10347 18056 bytes
SHA-256: bdb493368ea2a9a4ef8f40906d642fbe0b8f984cdb765822f560329d1856fea0
font_02_sfnt_off0001322a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1322A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1