Malicious PDF — malware analysis report

Static analysis result for SHA-256 1059da2bb3abeb33…

MALICIOUS

PDF

74.0 KB Created: 2021-09-01 18:07:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3700764d94bdec23667910471beeef2b SHA-1: 76ede924fd8a78a67a6eb4b63054504d97b7978f SHA-256: 1059da2bb3abeb338119abb1f4d86d52a250e555243c59bf3f28af85cba21607
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by a machine learning classifier and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various websites, some of which are hosted on compromised CMS upload directories. The presence of multiple external URIs and link farm characteristics suggests an attempt to lure users to malicious or compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://www.maderas-navarro.com/ckfinder/userfiles/files/fasofepebedupij.pdf In PDF document text
    • http://alimentosldm.com/userfiles/file/kisobalowafanukavifif.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/95646285868.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160820e9e4a8be---mizajanedukol.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7b98c9a3e---suduritonelov.pdfIn PDF document text
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/7842d346c30995c69730bc70b677c443/85290138502.pdfIn PDF document text
    • http://nontaromclinic.com/ckfinder/userfiles/files/bazanumetoxotixorij.pdfIn PDF document text
    • http://thicongdiennuocmiennam.com/uploads/files/67084423025.pdfIn PDF document text
    • http://yi-xiang-yuan.com/CKEdit/upload/files/tukexoref.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/9qcq8sc5a3tu2a7gu95hq64vq3/65753413349.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210727173602.pdfIn PDF document text
    • https://ifbscalidad.eus/files/galeria/files/15440048398.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/kodupad.pdfIn PDF document text
    • http://hz-karavany.cz/ckfinder/userfiles/files/79337479261.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/g58hrj22aiuags73174pn6j475/soselabupased.pdfIn PDF document text
    • http://assistance.uz/images/shared/file/kakofob.pdfIn PDF document text
    • http://www.kymenhome-etsinta.net/tiedostot/files/72336678705.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/51614062857.pdfIn PDF document text
    • https://binarbaidequipment.com/public_html/userfiles/file/lematijesimiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=acer+aspire+7738g+service+manualPDF link annotation
    • http://perfecturology.cafe24.com/upload/editor/imagefile/wewanonuxefogisuna.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_off0000bdce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDCE 11076 bytes
SHA-256: 6eb72d77b06e85f4cd4a9194cf2814daf54cc309718225ccb62c60c79e60b0bb
font_01_sfnt_off0000d7af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC1 16756 bytes
SHA-256: 1a7f5253a74b9fac7b2a7dec0433d69f1f0ee68e30b2422111ce3097bd09c9e9