Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a5fb4cee2285d56…

MALICIOUS

PDF

86.0 KB Created: 2021-09-06 15:05:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cc7e2d883d49ca34a0d54bad7ee765f0 SHA-1: 388f9bc635d3392e6edca98fb1d2dda813f26813 SHA-256: 1a5fb4cee2285d56378581ed3e83ff3e3a20d55a6c90737a44c89523583f20e1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this. The primary attack pattern involves directing users to external sites via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://queure.ru/uplcv?utm_term=lenovo+thinkpad+t450s+specs+pdf PDF link annotation
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/ah3qh1iihtmafoovnntl6hull3/27932830491.pdfIn PDF document text
    • http://aybar-gallery.com/userfiles/files/guzabog.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/8odroolnbdslosep8s6tas4uoi/14595090426.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/00fae66f22987fa464d32ef5eca40aa2/42198864363.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/55602619278.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/nolanolafuke.pdfIn PDF document text
    • http://congtyvima.com/images/Download/getafil.pdfIn PDF document text
    • https://redac.ch/upload/62197346032.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a253f35ceb9---posufox.pdfIn PDF document text
    • https://taechoclub.com/FileData/ckfinder/files/20210627_5E194899CB0BB9B5.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dae07188922---gawusaxokinetefuxedeso.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/d4f2aad479d194250b6257892b14816b/16679631888.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/22885240654.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/d67f13481f3c79bae6db0d91e417541d/41122102346.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/lunumaxeza.pdfIn PDF document text
    • https://locktactyuma.com/userfiles/file/mikolugexiwuludedukixog.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b51b92ef7f7---wenuwodewibarugo.pdfIn PDF document text
    • http://hvpeds.com/upload/contents/file/namonadatuxisibowumo.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076ba700c1f9---zuterelupugezexodidiben.pdfIn PDF document text
    • http://www.oneworldkarate.com/fckeditorimages/userfiles/file/nikegufoki.pdfIn PDF document text
    • http://wsm.hk/images/uploadfiles/file/vuzufesizaz.pdfIn PDF document text
    • http://4bx.pl/public/file/25341652990.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/nelevor.pdfIn PDF document text
    • http://taborcapitalpayment.com/clients/d/d0/d0a3925ee25d0adc8806453b18bccccc/File/bofunililokibewove.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/430e36c437ce8671d25b7a26a897e3b9/29885498430.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4ce140659---38101140366.pdfIn 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8F6 23772 bytes
SHA-256: 83af68d80f217c3b0c051dcc73f7bf6cfa3e43cee9e4b545d7073cdb96e14828
font_01_sfnt_off00011534.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11534 11020 bytes
SHA-256: 267cbfa09c092649b80ab5af950a592012b9a60cb5fa3e19f25fa655b5240bcb
font_02_sfnt_off00012ed4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED4 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
font_03_sfnt_off000136d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136D0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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