Malicious PDF — malware analysis report

Static analysis result for SHA-256 c65abd97fd34bed7…

MALICIOUS

PDF

81.6 KB Created: 2021-09-07 11:29:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1d233932a632fc77dcaf6fc3852e92ac SHA-1: 424e58ce32c1fc70cfe9a3d10d65fb86ae5398ee SHA-256: c65abd97fd34bed7fb96cbb398f6d1da813226093bca54444088fb6e4c57f5c4
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous external URIs pointing to potentially compromised websites or disposable hosting, suggesting it's used to distribute further malicious content or phish users. The document body was unreadable, but the presence of multiple links to external resources strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7642

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://chcial.ru/uplcv?utm_term=english+verbs+prepositions+dictionary+pdf PDF link annotation
    • http://dotbamboo.com/file_media/file_image/file/71097901275.pdfIn PDF document text
    • http://sampoernastrategic.com/uploads/image/files/64626384979.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/38b9fa4addf3ece040afd79812caf2aa/56890530608.pdfIn PDF document text
    • http://igabana.com/upfolder/e/files/20210808160427.pdfIn PDF document text
    • http://biemmecommerciale.eu/userfiles/files/sevar.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/77827447609.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/50816597466.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084d4e287199---vevikudejoporopu.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d382a569ec---tevodatadapanuj.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/99b9c2fdf8e33d640d9985ed41f704ce/mitazefijuxogegisigikefuj.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607acdbca53d7---44144263987.pdfIn PDF document text
    • http://osoboebludo.com/ckfinder/userfiles/files/35382634443.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/65998771283.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/tulunerofudovixufan.pdfIn PDF document text
    • http://op-gold.com/ck_image//files/selikifepidoruvituwani.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/gifojovero.pdfIn PDF document text
    • http://gimhaejazz.com/fckeditor/userfiles/image/jituwimewofasal.pdfIn PDF document text
    • https://baobihungphu.com/media/ftp/file/78555712450.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/zawadetesigel.pdfIn PDF document text
    • http://verkaufs-akademie.com/userfiles/file/nugekozixurobazuxip.pdfIn PDF document text
    • http://doremimarlikinsaat.com/userfiles/file/76758536952.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ea84ef90e---93887259778.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/74ee5885d6eafa40e949b9e671fe5ee4/mijol.pdfIn 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_off0000e23a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE23A 11200 bytes
SHA-256: 423878b82b4105a727c64323a3e6882684b2eca2d7fc2ef8b36b925a7163c161
font_01_sfnt_off0000fbf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBF5 18008 bytes
SHA-256: 1de4a542817fc4ac2d28cec07a0e0f46157727fec5c1297de65524b7b4706467
font_02_sfnt_off00012aa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1