Malicious PDF — malware analysis report

Static analysis result for SHA-256 54d943fc34f44086…

MALICIOUS

PDF

118.3 KB Created: 2021-06-28 04:15:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4460ae10a6dbd670cce06939c45bee42 SHA-1: 353c4e86028f96d06402f23ffb2d418efec368ae SHA-256: 54d943fc34f44086059ab16e23fd601c1145b51217e8d4b3edeca08894290f29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on compromised CMS platforms, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF's primary function is to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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 https://allytemp.ru/uplcv?utm_term=newton%27s+laws+of+motion+class+11+pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/4f244d9bcc668e1d0c4338786cf79c45/zamopigaref.pdf
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/20d1dbccd4578bbe651adb25965623e2/80109831581.pdf
    • http://flexa.cz/docs/file/fovenetigorof.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1606c833d0c2ba---87945472409.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a140df6b51b---79441041446.pdf
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fcd77084b6---ferivi.pdf
    • http://rzn-house.ru/upload/file/93666174895.pdf
    • https://dijitalsanat.link/upload/files/36331923899.pdf
    • http://cosyromania.com/media/file/45440189553.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/kfj6bcvj6a2u1o3m97qambios8/97646705688.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160c23c58c33f6---nukuxajikokul.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/f2fn3n943087caqe7iomnvgq8g/vinuvubisuse.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d43b192f9d---kurosoxafibukovusimipo.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/1taq7sm8koqo8m5dutadni3tht/52332472196.pdf
    • http://kartinatv.org/uploads/files/gezuwivupewotolimo.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1607e749406e67---96127845817.pdf
    • http://stacjaregeneracja.pl/userfiles/file/pikagopekusiruneridesit.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/d5beaf9ece1d3c0dbb666e2603228974/tenifamitazuwen.pdf
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/sc7ii7fl8vgvc4tln2p1sphog4/najevaxudulibupobexa.pdf
    • http://apluskleaning.com/admin/images/file/37406420803.pdf
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0f9348f6c---97524565832.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9fa701f079---14052782014.pdf
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/0203b231b915b9eb252799ee8ad65076/viruratawujobobititirur.pdf
    • 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_off00016b13.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16B13 16792 bytes
font_01_sfnt_off0001832a.bin
6a010002ef680750e6d6f1595e540d306f4ff731b471f75d6430628257555d2c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1832A 10828 bytes
font_02_sfnt_off00019c55.bin
ddcded94478cd265bbe427097de726e27b26297a8470cba75e16e7ff6ba77940
pdf-font-stream PDF embedded font (sfnt) at offset 0x19C55 17736 bytes