Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b147d933e4fb22…

MALICIOUS

PDF

110.0 KB Created: 2021-07-05 19:03:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a0521d002e4a1d0b673dc481434adc54 SHA-1: bf5912c9c68fb2f8cda808d1e0bb32be629e5980 SHA-256: 83b147d933e4fb221dd9e032e798a9530fd9ae742423e141f61281f7a57693f4
156 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs and link farms pointing to compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking readable content to infer a specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9819

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://wastran.ru/uplcv?utm_term=ice+age+continental+drift+manny PDF link annotation
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a920bb0dcd9---kunotatisomal.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0ecbe06044---wojumawo.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/0114b6c69264235ebad092ba5e2ea8a5/41177229867.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/sqi1s557kt63a8gti0lecehkd6/41328258747.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090d0b0d774a---bawetewuginaxozokumamumol.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608017ed1238d---40863421045.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160c538bbc028c---35251528380.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/111f1c8a2f4510f16fc3d7105eed3937/65326335052.pdfIn PDF document text
    • http://auroraenergyproject.it/userfiles/files/7466002608.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/78f6624ecf84edc1af15bfdff85bce9a/sadinotiriruxirobuwatu.pdfIn PDF document text
    • http://kme-kme.cz/files/file/bukujake.pdfIn PDF document text
    • http://maxbrio.kr/files/files/wezuretanuxu.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160715eedb3c37---pimewe.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/0c667d9750f424486839ba09240ff14c/81838484803.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/fugulugatujolaru.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d692a60d3df---55401879360.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/sfgnle3jcne8fvfkbk1krbois0/25846168663.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081a0a6e147b---91797150120.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cce59aa811---feweme.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/9558802a5f6dd8a0444105c88865bca6/51192004738.pdfIn PDF document text
    • http://tillmanfamilyreunion.com/clients/b/b7/b7385abc5988d1ee605fea7695e3d00e/File/xezuw.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/amegd7ena70lh3u83eluuc9ov1/denutededilalimu.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/e75435d8c91115e09016d77dd2f2267a/minelavu.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3cd86d9c3---50894692010.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4c9844a1c---111524914.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/25924f6a6665a34fa1307ade89ad315b/rejinaluwizafofilijufov.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://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_off00014f18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F18 16916 bytes
SHA-256: a53d46ff009ca63a568e7bfc85fba4cb4f043f58df74752a1d81cf3dc564b2ab
font_01_sfnt_off00017b0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17B0C 10716 bytes
SHA-256: 6cbe21386b15eeab6fec4ad9ff6b062e9e0faa223426fa60069fb4112a0e1104
font_02_sfnt_off00019372.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19372 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1