Malicious PDF — malware analysis report

Static analysis result for SHA-256 31f8d73ae52a7000…

MALICIOUS

PDF

84.4 KB Created: 2021-09-02 09:48:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c4a84c26e778e6d18ecde510fbcbc2f9 SHA-1: c3759e0b94aedb17e04e9309356b286187418d3b SHA-256: 31f8d73ae52a70000740a58bad903dc27d2982ee07c77ebe078810c89b1d699f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It functions as a link farm, with numerous embedded URLs pointing to various websites, some of which are hosted on compromised CMS upload directories. The document body is heavily obfuscated and unreadable, suggesting it's designed to hide its true malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://hurtmar.pl/Upload/file/59558536861.pdf In PDF document text
    • http://ciarajewellery.com/editor_upload/file/sojupotavidanu.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf497638b3---96015127254.pdfIn PDF document text
    • https://memoservicesrl.it/file/nojilukanusanagevukumim.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/161011bab60331---6368126962.pdfIn PDF document text
    • https://nasroglobal.com/userfiles/file/jituxudilanixibazijezizob.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607203c46fc7f---65995938093.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8476f89f53---95606388169.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/8c33b979866affbbef40e40b0150b288/86669660697.pdfIn PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/wefowefenodagozowozo.pdfIn PDF document text
    • http://mexxeopaint.com/upload/files/pomuruwulotu.pdfIn PDF document text
    • http://avsa.org/sites/default/files/images/files/leferedejurewometebiwaliz.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/4e81876d254b7873b0181b1f55856de5/7073225941.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/59752944302.pdfIn PDF document text
    • http://bjxbw.cn/userfiles/file/negubizawofasagora.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/4bf087edc1102922336f1f363e2470db/13757610232.pdfIn PDF document text
    • http://www.ih-consultant.com/ckfinder/userfiles/files/89003016747.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/falutulatalujugujijili.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/zifudevenobejudiwipux.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/aeb8976a521e9a5bf9295e98b45e58a2/solubu.pdfIn PDF document text
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/c059bb86f2f4b8b61f2cfadf2ddd6e04/2843465285.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210801210938_c9eehx.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/5077r1p472robgrden9qnuc1s9/vovevibopexi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=all+breath+of+the+wild+weaponsPDF 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_off0000e69d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69D 16960 bytes
SHA-256: a8f6509c4a30824815ed550c219d54acb1889afb737aae3389b9c29876c27a6f
font_01_sfnt_off00011261.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11261 10804 bytes
SHA-256: c568a8ad281e46dbbfe3ab91ea292d7b8d8ab19de96a1a1a85e5c69e58cb41e9
font_02_sfnt_off00012b11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1