Malicious PDF — malware analysis report

Static analysis result for SHA-256 48c40f875a2d4f32…

MALICIOUS

PDF

99.4 KB Created: 2021-06-01 09:28:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: f2c7cb23a6348dc93815b48c1cb625f6 SHA-1: 0b81408e6de351468447905c7612048b461f7d4c SHA-256: 48c40f875a2d4f327c6fbe0836bc86f28c2454f9b8c13b8b7db7721797fbd9a8
186 Risk Score

Malware Insights

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

The PDF file contains a link farm designed to redirect users to external websites, one of which is associated with a lure for 'Appserv windows 7 64 bit'. The presence of numerous external links and the ML classifier's high confidence score indicate a malicious intent, likely to phish for credentials or deliver further malware. No scripts were extracted, but the PDF structure and embedded URLs strongly suggest a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • 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.
  • 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://baarspo.ru/123?utm_term=appserv++windows+7+64+bit PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4412415/normal_604ec1a9bd3ce.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371800/normal_5ff1dbdc67daf.pdfIn PDF document text
    • https://zusiwugebibod.weebly.com/uploads/1/3/4/4/134484471/koxonolevemuriw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481173/normal_5fdc55ce60972.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366665/normal_6016b34d64403.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450355/normal_603a705884406.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450517/normal_603ccf713e9d0.pdfIn PDF document text
    • https://dafepigog.weebly.com/uploads/1/3/4/6/134605944/9f8be5.pdfIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/957f81f8-70f6-4b25-ab3b-c4e949045d0e/codes_for_slither.io_2020_july.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d3deddc1-5720-4eb0-a451-59b2f6fd2aad/how_to_make_fermented_pineapple_juice.pdfIn PDF document text
    • http://fotikeralo.pbworks.com/f/how_to_create_a_workout_plan_for_building_muscle.pdfIn PDF document text
    • http://sijomirurefi.pbworks.com/w/file/fetch/144449733/how_to_connect_my_3m_worktunes_bluetooth.pdfIn PDF document text
    • http://palixazoke.pbworks.com/w/file/fetch/144427254/como_hacer_autos_con_cajas_de_carton_para_nios.pdfIn PDF document text
    • http://zezimin.pbworks.com/w/file/fetch/144422748/74999756095.pdfIn PDF document text
    • http://gatasulupu.pbworks.com/f/sirejekowituf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b4a8a24e-0f28-4046-bfd0-0144d7b10061/putalogaweg.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://www.gnu.org/licenses/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00010345.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x10345 16072 bytes
SHA-256: 48ec81eecd6cc5417761cbd0eebb488c99f1ac4f7402d1745870b1ac2a7c91d5
font_00_sfnt_off0000f1cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CB 5104 bytes
SHA-256: aee2f14d470d5311a11db03a165fd6ecf06c9fb9e1b487229ce02fc8671c6e7a
font_02_sfnt_off00012eb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EB5 14436 bytes
SHA-256: c3ac37af38bc97c5003cc71799dda5abbf76b72308a8757dcefcf88fc1d916ae
font_03_sfnt_off00015bec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BEC 16204 bytes
SHA-256: 532315dfdc59b350d447ad91845dd8cc72a836e684f536ab9a4305dc5b53fb8e
font_04_sfnt_off0001711c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1711C 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176