Malicious PDF — malware analysis report

Static analysis result for SHA-256 85853c3361983663…

MALICIOUS

PDF

71.9 KB Created: 2021-07-19 05:47:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 9367287ab0da0c680a68b30e20f46f58 SHA-1: 8e3e312bbd553513302ae177a5a3bf516ea40c0a SHA-256: 85853c336198366319bab75432aecab9956d5fe27d44094333ca6038919b2cdd
156 Risk Score

Malware Insights

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

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a phishing or trojan payload. It contains numerous links to external websites, many hosted on potentially compromised or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF-specific heuristics related to URI and link farms supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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://aradovan.com/userfiles/file/kifisutudoravetoxarumuk.pdf In PDF document text
    • http://www.sealjet.mn/pictures/files/26425350405.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ubi3lpqu911r9pbnhpn7tp6kn2/92597376287.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/givoduvadanavewakazabo.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/91863297107.pdfIn PDF document text
    • http://proxima-design.cz/files/file/56941754126.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/dugifagusadirojegomefon.pdfIn PDF document text
    • http://wenxuezj.com/images/File/13363489804.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3379a9442---92538968437.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baba6867486---43139420381.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070746854379---biwopomezi.pdfIn PDF document text
    • http://gomientrung.vn/uploads/image/files/xikaminu.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c45e0610360---65575524735.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/39772232237.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/etnvfak0vkokfdeg0arbf239ab/78010603350.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092aa222d852---defexirukatuwunekuv.pdfIn PDF document text
    • http://meta-min.com/files/93339067862.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/24193390018.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d17376cc4---91771508125.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/gaargo68flh9773l0c7b1257u2/86156398516.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/b7lhurnkbrhinv4rv8s28q7ep6/wepodisikebipenuxaz.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ad7756f2466---34645921441.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160f021d1b245d---65972191660.pdfIn PDF document text
    • https://vibangthuaphatlai.net/uploads/files/zexixewuw.pdfIn PDF document text
    • http://www.deewanalarab.com/up_imgs/69165686188.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=county+jail+numberPDF 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_off0000ba64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d27b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD27B 10616 bytes
SHA-256: 6664f1a6023430912dec13d2da02e8c3a08877e2a8df9ef98ed43ff15735e32c
font_02_sfnt_off0000eab9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAB9 15436 bytes
SHA-256: b20e087206f39f144353afe771418c970ec1622a0c046ab9a8e0259271b679e2