Malicious PDF — malware analysis report

Static analysis result for SHA-256 b28cb510c8074320…

MALICIOUS

PDF

87.8 KB Created: 2021-06-26 18:42:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3bfa5d27bcf53d24149eb729ca6aafff SHA-1: e86253efd0ccb2351a993e39d8144d396a780291 SHA-256: b28cb510c8074320328d6fb30d1c8e969cd690f7a74b230af1ae69bdb0ed5e58
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised CMS uploads, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, but the presence of external URIs and link farms indicates a likely intent to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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 http://thunderstar.cn/userfiles/file/20210624115446316104198.pdf
    • http://arcadia6465.com/clients/f/fc/fcac8d81e62e7f23ed02b02243def538/File/nonopevidexukuvufe.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ae6834bce41---pijep.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/jl5tu7acclq4fi4oj51dvmgsle/lekodezomesatul.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/b010bf67b1e9dd47fc1b2450a04c3dc7/nizajem.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160731ca108c87---nolurado.pdf
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/0fbkd6i509tldt789pkksrte2q/xowotiwozo.pdf
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/ldthrt1k594bj05261kkdgausv/11937303399.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609f4d601924d---44904498344.pdf
    • http://tasteofruraleurope.eu/upload/File/31885064317.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b243393d2---29063231346.pdf
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/d7epu564vat0129lvekia6pjk0/89358467307.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb1d50a22a---76755476561.pdf
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/60811099730.pdf
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/160797fa2483c7---33289732411.pdf
    • http://atdawnwelift.com/userfiles/file/61489502906.pdf
    • https://yingzhaoliuart.com/upload/file/golojigodaxomubozipalu.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/0qtg64u4mv8sjag15jk63e44cm/8374383973.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081e7cf3ed6f---ratopenexo.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160be5f529f239---gatiwu.pdf
    • https://soportedevida.mx/ckfinder/userfiles/files/17816658405.pdf
    • http://tumwebthailand.com/ckfinder/userfiles/files/vofipodazirilafulojawugo.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/160783a76911c5---25938920109.pdf
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/g6uqu26csutco2ku1dk5btb0r0/gusidajetiboj.pdf
    • http://chieusangducphat.com/uploads/userfiles/file/50464857358.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=bdl+to+aua
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efaf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAF 16792 bytes
font_01_sfnt_off000107c5.bin
79012037cc3dfcc2f222e4de424500ef741e606f1db761be03adaab59d21ec65
pdf-font-stream PDF embedded font (sfnt) at offset 0x107C5 9796 bytes
font_02_sfnt_off00011d5b.bin
1e46ee7f389d4427a9b20869a5d38ead87b837863126a158e306a7afe741294e
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D5B 17076 bytes
font_03_sfnt_off000149e8.bin
15171638d69c9281a983de8a04f8d213e5ed86d33053034f6aa0dd130c4010d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x149E8 1700 bytes