Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c6c4c07b57addc6…

MALICIOUS

PDF

89.6 KB Created: 2021-09-13 00:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d8dcfeb7a3bb86096bc386b38ba24f5e SHA-1: 9d055a71835fd98a90885a52494cf1d8c7598fce SHA-256: 3c6c4c07b57addc6824bdd2a5cb0152b1225da6f24a948cadfd4646070cc5959
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://wwsm-us.com/files/file/25206122877.pdf
    • http://escritacontabilidade.net/fotos/news/file/lumegajatezaw.pdf
    • http://brandiassociati.it/userfiles/file/73830660873.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f391d3469c---3090263024.pdf
    • https://eseninternational.com/uploads/files/22999340814.pdf
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/eaa3afb81426dd4076a6082cd9b35d70/vosarapimidod.pdf
    • http://brilsports.ro/userfiles/file///33517379827.pdf
    • http://chieusangducphat.com/uploads/userfiles/file/67114045457.pdf
    • http://ibconsulting.it/userfiles/files/96398265875.pdf
    • http://abwcockeysville.com/uploads/files/vokurasiwituruludowazudus.pdf
    • https://chulintemple.org/CKEdit/upload/files/9512539643.pdf
    • http://www.sport-konyv.hu/userfiles/file/femasodes.pdf
    • http://nuitsdartistes.eu/images/file/81940937556.pdf
    • http://schokofontaene.de/idata/disofisaxuwosujevumufi.pdf
    • https://relaxbotanika.cz/ckfinder/userfiles/files/4039850471.pdf
    • http://goldendoodlesofthesierranevadas.com/userfiles/file/gejopelobofonubeg.pdf
    • https://medpressa.ru/files/file/rinekerab.pdf
    • http://templeton.sk/userfiles/file/novemamijikibor.pdf
    • http://storemisr.com/uploads/files/41122533058.pdf
    • http://h-st.nl/bestanden/files/wowebadipa.pdf
    • http://baby-daycare.com/uploads/files/202109031357083761.pdf
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/tilixekakamijov.pdf
    • http://tortsurprise.ru/upload/redactor/files/88714752349.pdf
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/5f64eeece1e15d4f2f0bcbc51be53a67/73298530230.pdf
    • http://chelseafoodmart.com/uploads/files/5530677958.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16136c9ecc95e6---zogivurikasijeba.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=best+realistic+driving+games+for+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa36.bin
ad1335317db09cf2f647b41ef0c58ca708017ab5ed3b12b23e1dc4669112621b
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA36 17296 bytes
font_01_sfnt_off00012713.bin
48712dbac0a0dc3f875acfd7cf74b3581618b121ee6b727892e28e3801180c79
pdf-font-stream PDF embedded font (sfnt) at offset 0x12713 10940 bytes
font_02_sfnt_off00014045.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14045 16792 bytes