Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f019770f622027…

MALICIOUS

PDF

88.6 KB Created: 2021-08-13 13:46:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: 3f2f44fcc0e2067babd3c8c0121b6a39 SHA-1: 9b90d27e69f688a2bf0d46377c6024ae0e9119c8 SHA-256: a4f019770f6220277064f9c73b4b446d2207ad2b10c3d2008795925ff5a9eca2
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://coutleelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/9082764124.pdf In PDF document text
    • http://ukwoodrecycling.com/userfiles/files/81417299272.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/dobuvem.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/netumiwanakigeruxotigawo.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/pjo6f44dmml01dms3nih536p0p/18913308117.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b3774ce96---94163889407.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160c41742d7ede---kulezorozototove.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c2944d02ff6---lexosinukamolutuxo.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/68376d4885d8fb5e5abe3c21bf3d9208/299260008.pdfIn PDF document text
    • https://apgr.eu/UserFiles/file/xobevodokekegezexe.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/411ec65243867f4ddc4d46c3d6a3175a/fifamud.pdfIn PDF document text
    • https://a1-recruitment.fr/v2011/Files/fck_upload/file/76191290074.pdfIn PDF document text
    • http://ifa-astrologie.de/userfiles/file/soguneva.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/sazetapirewibexis.pdfIn PDF document text
    • http://year-c.com/upload_fck/file/2021-6-4/20210604183114772864.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/a3df4df2c294593483d9d32007224599/pofojozutirugotaxo.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160a37d16d2683---bosijamezafudupokudod.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607266a714b95---20587115090.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076ac875404f---wexurabuv.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/905d7d461278cd8a1d497b2c9fa09f93/jowixibulogovikujuramij.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/f523916716dceb8b47d8ae61ae2413d0/vujosodij.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160bda48294ea9---xopifuwufolozuvubafeki.pdfIn PDF document text
    • https://hagepoorter.be/files/files/gozomolokulosap.pdfIn PDF document text
    • http://truhlarstvisollner.cz/data/file/32232895280.pdfIn PDF document text
    • https://ph2020.org/FCKeditor/file/wetupapovob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=cbse+class+12th+biology+important+topicsPDF 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_off0000f4b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010cc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CC6 17088 bytes
SHA-256: d9d71b94d9db9d2d9a05144df1c3db1ce843fe75db962f506b20cbb1445a973c
font_02_sfnt_off00013974.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13974 11276 bytes
SHA-256: 0a439e9562a5b9f83c6278be84c6d9c89430044cb4984ae864ae0633a1da4360