Malicious PDF — malware analysis report

Static analysis result for SHA-256 c31fcd06391a9505…

MALICIOUS

PDF

97.1 KB Created: 2021-09-07 16:56:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 589e027285097b7dddf5ff93d782f437 SHA-1: a031853b87d2d2986702db5a83f8ba329c58ae59 SHA-256: c31fcd06391a9505e468e56437451b7c2c0d756af1757a62e8e9f0709536e8a7
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a password-protected-archive lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://nirmalapublicschoolerumely.com/userfiles/file/20818776176.pdf In PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/ad604bf5d399753c1f5a91f10813a915/welebalutamax.pdfIn PDF document text
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/805948d427704ff006f33df3820f0d7c/18665260704.pdfIn PDF document text
    • http://rheinmotel.com/userfiles/file/24095433217.pdfIn PDF document text
    • https://hinodanang.com/uploads/image/files/bexarisoze.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c7da2172b---takugumur.pdfIn PDF document text
    • http://badaranquehablar.com/userfiles/files/wopalidokupuw.pdfIn PDF document text
    • https://sheenabusesandcoaches.com/userfiles/file/balipituridevaparobikemig.pdfIn PDF document text
    • https://automatisme-portail-bordazzi.fr/userfiles/fichiers/24217054612.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af7faf262af---kexogoxapibalu.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/7744124508.pdfIn PDF document text
    • http://canhtoanland.com/upload/files/82883471998.pdfIn PDF document text
    • https://manualismedicina.hu/fileok/file/5116152953.pdfIn PDF document text
    • http://konstruktor33.ru/app/webroot/files/files/damogejidigorubo.pdfIn PDF document text
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/a3bee36d82fe7fba2ee0ecfae3321088/rawajowini.pdfIn PDF document text
    • http://ogledalata.bg/uploads/pages/files/28698237421.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108f98cda5b1---kipakomowodilozuwifudis.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160913f9d8342f---12960408324.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/ad49d4240fca034a603e15b90a29d609/18305722308.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/8kb8crij4rr9fg8pv3pajceuau/gidukuwomekan.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/339b16be2a1d2ac80fc54b2b48ddec32/zumedukimajizawofibivuj.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/zetonesosudetizedonanete.pdfIn PDF document text
    • http://sllight.ru/design/img/upload/file/14275856055.pdfIn PDF document text
    • http://horizonpestservices.com/userfile/wunifubafuboxed.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=terminologie+m%C3%A9dicale+et+physiopathologie+pdfPDF 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_off00010c6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6D 21572 bytes
SHA-256: 48dd3d74e6b5dff5566858bdc045f12dee7dc96702196245656533d5a5b65b53
font_01_sfnt_off0001420f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1420F 11296 bytes
SHA-256: 187f723d2910cca92e4cd48f6a838d6de9229caaf2df0d1a882b468bcea1d196
font_02_sfnt_off00015beb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BEB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1