Malicious PDF — malware analysis report

Static analysis result for SHA-256 88dafb15081072a3…

MALICIOUS

PDF

97.7 KB Created: 2021-08-14 14:36:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e0494337714bba1fbb002a13244cc260 SHA-1: 5ee7abc949a50cad9eeb956c6d2dd9f1304ffd7d SHA-256: 88dafb15081072a3c313a39131ea4abc05bb9a3d8a9007737decfb0647334cf3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous external URIs, many of which point to compromised CMS upload directories, suggesting a link farm designed to host or redirect to malicious content. The presence of embedded JavaScript, though not explicitly detailed in the provided evidence, is a common vector for exploiting PDF vulnerabilities or initiating further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160b54755bc4f7---71535818942.pdf
    • http://szilasfood.hu/pic_upload/files/95507821329.pdf
    • http://alexanderjamesbackcatalogue.com/userfiles/file/bibozikipinifuja.pdf
    • http://banhangcongnghe.com/upload/FCK/file/40032863646.pdf
    • http://ktcz.eu/files/files/dufusunepimurutunoso.pdf
    • http://thelewisfamilyreunion.com/clients/c/ce/ce72a6ed4f7059d305e3bbfb121cee90/File/68632080373.pdf
    • http://global-leasing-management.com/uf/file/zototodejuw.pdf
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d80da581a---65656516465.pdf
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/5ae9ef043c9621edc78f1a9c3ee1e863/gobefikakogewinow.pdf
    • http://vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/rufogafopit.pdf
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/jinezovuwituvarup.pdf
    • http://alexandraharris.com/clients/36054/File/67913943908.pdf
    • http://vtaky.sk/media/file/dujikozurumotozepamiwa.pdf
    • https://bonacorsi.it/file/90472900233.pdf
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160c31c010963a---mudabexazujopofe.pdf
    • http://nkmate.com/FileData/ckfinder/files/20210701_B559F4DF8A548326.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/01201de290fe52348f898b0b4ddd3ca1/nizosisibokedowoge.pdf
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/a796f998e0eb2e039e8b265adaeecb14/befusodubuwaxel.pdf
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae89fd0794b---91283695177.pdf
    • http://thietbixanh.net/uploads/files/51234716147.pdf
    • https://iva-vietnam.com/userfiles/file/detedolulozerugum.pdf
    • http://01host.ru/userfiles/files/24734593837.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/425c70052fcd8c3b38f67168e1d8e189/povifisurakigowimuzum.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=describe+the+steps+involved+in+marketing+research+process
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001183f.bin
578e23bb02b951ecd8185a6dde5b3cbe78e01be59fc37690ae0b6b3d6fc44887
pdf-font-stream PDF embedded font (sfnt) at offset 0x1183F 17268 bytes
font_01_sfnt_off0001457e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1457E 16792 bytes
font_02_sfnt_off00015d95.bin
dd3b0854c07049d96118e31185d5be6a450bae8208530f935fe767860e076862
pdf-font-stream PDF embedded font (sfnt) at offset 0x15D95 11260 bytes