Malicious PDF — malware analysis report

Static analysis result for SHA-256 87927e33eaa78f7c…

MALICIOUS

PDF

60.8 KB Created: 2020-10-01 00:49:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: b57e5c694ff63dcd6798cf3d0c5ca1ff SHA-1: 4b5bcabed2a940cac825ee48b4ee913e79eff8a7 SHA-256: 87927e33eaa78f7c91e02c9648d504edced83bb7ac65ef05c1f5dd7cb1aa7bad
224 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document containing a large number of external links, many pointing to disposable domains and potentially malicious redirectors. The ML classifier strongly indicated maliciousness, and the PDF structure suggests it's designed to host a link farm. The presence of a URL like 'https://ggtraff.ru/strik?keyword=base64+decode+pdf+python' within the document body indicates a potential attempt to lure users into decoding content, possibly to reveal further malicious payloads or obfuscated information.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • 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://ggtraff.ru/strik?keyword=base64+decode+pdf+python In PDF document text
    • http://suguz.weekeepcompany.com/uploads/1/3/1/1/131163601/kufinadanu.pdfIn PDF document text
    • http://files.wwccoc.org/uploads/1/3/1/0/131069819/kutapu.pdfIn PDF document text
    • http://xituwuk.rachelborgman.net/uploads/1/3/1/4/131453134/vugesaradujerez_ruvobanekek.pdfIn PDF document text
    • http://labajuw.mindyourbodyfitnessandnutrition.com/uploads/1/3/0/7/130775940/6038090.pdfIn PDF document text
    • http://nikoduju.rcfenceanddecks.ca/uploads/1/3/2/6/132681352/dusub-saduxi-letakapekob-jeberufesonu.pdfIn PDF document text
    • http://ziposela.californiamobilenotaryriverside.com/uploads/1/3/0/7/130776074/zotitusovodebokipaw.pdfIn PDF document text
    • http://files.floydslighthouse.com/uploads/1/3/1/6/131606179/bfa50b4fbf5f.pdfIn PDF document text
    • http://files.abocomix.com/uploads/1/3/0/9/130969740/6639977.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/7332/2664/files/10145951514.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0465/9252/4453/files/lodge_grill_pan_steak.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1ea55a6e-c30f-4ad6-9bb9-f13615935b90/83904981015.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3930ef3d-a1db-4a48-bf6c-05368d27e473/71762283456.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/85d2fd75-a00a-429e-b5cd-5df0948617c9/towubasodifozupezo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/663712b5-99c5-43fb-8cca-26dbc4794dfb/32712133595.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bdefe674-1999-4eb6-b480-b4cd19ba1432/rowexuga.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000067c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x67C0 21976 bytes
SHA-256: 29b243b250a1185cdad755e8ebd2c50f768e2be66c3d02be26c39858dac630ff
font_01_sfnt_off0000ac7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC7D 5508 bytes
SHA-256: 27701ff4a5d3f6754c2d3aed68a28db2d75bb5ca81e1467e0d05d992d503a2da
font_02_sfnt_off0000bf4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF4B 10584 bytes
SHA-256: ced0435f754921659499b55d2ce945be1995480f4be876c8c3c96ae72e70cce4