Malicious PDF — malware analysis report

Static analysis result for SHA-256 131b251eaec4d3b4…

MALICIOUS

PDF

90.5 KB Created: 2021-06-09 15:44:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: f6b6597c18607d16a5e5e966a829fad5 SHA-1: 53b78e8983537880a147a49340d207615182972f SHA-256: 131b251eaec4d3b496ff98db78f2015a19c7c545816beb463081c186cc7225df
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

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

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=restoro+software+license+key+crack PDF link annotation
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf231a367d---52289315175.pdfIn PDF document text
    • https://maturana.cl/upload/file/2044437547.pdfIn PDF document text
    • https://securitegenerale.tn/userfiles/file/10972076888.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/ff05da94170141d22e9a0b74f5caa7d4/fivurubud.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607db15ee6deb---pilexikomavezufegalusul.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/1fcb0069123f25335d0f338484b046dd/29233147316.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/0f85987b410af205b048a7cfa3d3ceb2/fajinekazusederirorufeku.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/a9ecebaf5e0d047bd8de607919d9e449/64421302185.pdfIn PDF document text
    • http://mbcasc.net/imgs/file/2739113563.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/eea226ee98b6c30c79e5a68fcab2b0a1/wositubazebarijuvunakuxa.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/0ogdrq2v70erh53j7hkts1avi7/didatevolipufotuletudoji.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/giwazogarifipaxinu.pdfIn PDF document text
    • https://www.temsilcifirsatlari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160808bd50bcd9---40262890668.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/65660093.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/da5a71c41927653150114f67da1c2718/19999431403.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off00013c8a.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x13C8A 18952 bytes
SHA-256: 2783b8db5b81e12a7f03050359793f43e0cc61220784cde8ce73ae86fb59b34d
font_00_sfnt_off0001047b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1047B 5140 bytes
SHA-256: 52162e9ea9d3f7daa98e4b75147a0fe6032bac1aebe93f3db06ad92315d547f9
font_01_sfnt_off00011625.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11625 11300 bytes
SHA-256: 9b5e4c2a530cec59534edb926f3f7606460f3e47374e77949048907172d61a3b

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