Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a5b3a3da09a1bfa…

MALICIOUS

PDF

88.5 KB Created: 2021-09-04 16:18:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 72a7960a24d7d8488a51b7ad069a8c30 SHA-1: ef4a9fde8da5e30dc0178dd227b7bc6efeb79771 SHA-256: 8a5b3a3da09a1bfa988f41b5389848c45d91a091aedfe26fd025ab9180b14246
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories, indicating a potential phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further supporting the idea that the content is not user-facing but rather a vehicle for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://perilatomsk.ru/ckfinder/userfiles/files/witomevogafavetaselud.pdf In PDF document text
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/2966216d7ec026cdf9c394e85248660c/40070882643.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160725cef95cf1---tibagiviruxudukovag.pdfIn PDF document text
    • https://lapalettedesarts.fr/gestion/file/57472050588.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f5bef2c8f08---munavukaxugukefewelom.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd57f649a2---zobenukog.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/8nkph35qle291fm72n708ij902/85739629648.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1607274779091c---86777235779.pdfIn PDF document text
    • http://www.christianhouseshare.com.au/ckfinder/userfiles/files/viwefetixas.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/45160411166.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/pelezomegupadinafesovogup.pdfIn PDF document text
    • http://trendstyleimage.com/uploads/ckfinder/userfiles/files/4079569970.pdfIn PDF document text
    • http://fittbike.hu/files/file/31371252681.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160fe5a4c7466a---40006574556.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/3d5f6a1cde1fde4c43bbafe77dafc8e0/28363681001.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc2dcf15db---12912122275.pdfIn PDF document text
    • https://paron-rebondir.com/uploads/files/bupodazom.pdfIn PDF document text
    • http://theofficefurniturestore.com/ckfinder/userfiles/files/63034539667.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/27879524166.pdfIn PDF document text
    • http://grgct.com/ckfinder/userfiles/files/84415027360.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eab9c70cb3---mexazudisirakotin.pdfIn PDF document text
    • http://h-p-n.fr/catalogue_dynamique/file/78070811848.pdfIn PDF document text
    • https://sssmri.com/ckfinder/userfiles/files/pizatebatuwogumigagajipan.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/24108798432.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074585805b34---kudavabazugevakibe.pdfIn PDF document text
    • https://www.stock2morrow.com/ckfinder/userfiles/files/nabivar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=elkay+ezh2o+owners+manualPDF 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_off0000f34b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34B 10740 bytes
SHA-256: ccd346ddedc1ea76637bd570c8bd9517605a6d6dd0be449a010ff6ee56e1a52f
font_01_sfnt_off00010bf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12407 18100 bytes
SHA-256: f8e8c7da4a588125c9c6f7b3e8a60e52afeade54e84f3f2ee2422c60bf58d660