Malicious PDF — malware analysis report

Static analysis result for SHA-256 56443386d31be772…

MALICIOUS

PDF

74.4 KB Created: 2021-09-09 11:59:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8e1c94c10f7f7ca584e543f5e630427d SHA-1: 0321eaab9f5d2635964a60acc8b4a0a2e7b7bf84 SHA-256: 56443386d31be7723f47f3cb77f3b0fd6dce1226bcf2034040d9be8ea2f6321c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple distinct hosts, some of which appear to be compromised WordPress upload directories. The ClamAV detection and ML classifier further indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.bandungmesin.com/file/3375237131.pdf In PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/kamixopadudabowixob.pdfIn PDF document text
    • http://lingvastar.z-i-g-z-a-g.com/userfiles/files/10449637418.pdfIn PDF document text
    • https://matricula.netlandschool.cl/files/68434339989.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///57126621102.pdfIn PDF document text
    • http://conservativista.com/js/ckfinder/userfiles/files/54945711794.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/36287379257.pdfIn PDF document text
    • http://eventclub.pl/userfiles/file/70277276168.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/23661267947.pdfIn PDF document text
    • https://norservis.cz/files/files/tenikofuwux.pdfIn PDF document text
    • https://ans5680.preneed91.com/upload/files/18159642551.pdfIn PDF document text
    • http://wannawwannie.pl/userfiles/file/32712368867.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/b513d8672e866e4e89ff5371837842ab/wufikuketoxudoninosuvo.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/wenilifefa.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130938288386---63968567889.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/neluxuresedevofiduzawige.pdfIn PDF document text
    • https://anbuadidravidarmatrimony.com/ckfinder/userfiles/files/redig.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161324bd8678ec---bimikutajuloz.pdfIn PDF document text
    • http://oryginalnedekoracje.pl/userfiles/file/xetekopej.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/24679928355.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+connect+mobile+to+pc+via+usb+cablePDF 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_off0000bec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEC5 17484 bytes
SHA-256: f7b9b211ff67982684fbf1c976f9bc6994132dd418e19b32b5c51f94ff8922a8
font_01_sfnt_off0000eba7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000103be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103BE 10820 bytes
SHA-256: 85ebed2a5d1c1949c13206c634aa0d6832fe342ad0f6fc547d765e0ce5933b36