Malicious PDF — malware analysis report

Static analysis result for SHA-256 31e9ad0b833c71bb…

MALICIOUS

PDF

91.0 KB Created: 2021-07-13 07:01:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: bead405985c000036c0c114e23bcc97a SHA-1: 14037621af27f915a5c336d2615800ec46bc3691 SHA-256: 31e9ad0b833c71bb7cf8bc2b1ef383a0492acdf17fe31cf9e975fb2ffebed4b4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple links to compromised CMS uploads suggests a coordinated effort to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/7f675e4d4fa55ac3b84f45a1d1a88adc/pusesobubipopekodebomivak.pdf In PDF document text
    • http://slippersymposium.com/clients/875641/File/85130323771.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/14859162411.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/v3vei20qoka2rckqd7rcq0263n/13318188335.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608430ea16d47---zutarilorepagasoriluta.pdfIn PDF document text
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077163a0df30---vubegab.pdfIn PDF document text
    • http://trungtinjsc.vn/upload/FCK/file/115916961.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160987ade8adde---23113881043.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c48c466d916---42301790762.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609e52014f181---pidogajofusexurenesi.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16095cd3cabe03---vakefulazivapak.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///bitinokekogedojadorufo.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/4475dbb429595cd0c0608d03ceb6ba32/zedobimawulokuxi.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/b785d5c5ba5f7b7771865237ae586a45/49874183206.pdfIn PDF document text
    • http://loaamtran.vn/files/usersfiles/files/mabiliwidegedotimike.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794c73de4ea---witojuvegijipaxu.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/08082404790cfc7ad2b2f66a963a116a/68015482825.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bbf05ba6cac---28774287700.pdfIn PDF document text
    • http://artside.org/data/temp/file/vimonigurumes.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a50abce368b---61620569169.pdfIn PDF document text
    • http://cleangroupbd.com/ck/upload/files/12620261863.pdfIn PDF document text
    • http://huile-de-nigelle.info/userfiles/file/tedodolale.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/zekivabesuvo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3acdf88ace---lidupojexugimixi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=no+time+to+waste+timePDF 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_off00010493.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10493 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011caa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CAA 10080 bytes
SHA-256: b1b77715538a709483532cb96454e4f5293ecd69622f66720b4003494f4fd060
font_02_sfnt_off00013340.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13340 16856 bytes
SHA-256: 842eebe47300279bf21d845e3afd7679ce6079c0d04857f573e27673df2ebaef