Malicious PDF — malware analysis report

Static analysis result for SHA-256 99871f66be40da1b…

MALICIOUS

PDF

78.9 KB Created: 2021-05-25 10:03:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 1cb4c633fa53ba479e9dccafd1c7b46c SHA-1: b42e46a170ac0b5e5245f13370424f4640afafae SHA-256: 99871f66be40da1b52a0eb30575f73a6e9f69c74a217afedaaf74b4470a181cc
196 Risk Score

Malware Insights

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

The PDF contains a mass external link farm and an SEO redirector disguised as a guide for game hacks. The primary malicious URL, 'https://gimoguvi.ru/strik?utm_term=how+to+get+ice+hacks+on+surviv.io', is used as a lure. The PDF also contains numerous other links, many pointing to S3 buckets, suggesting an attempt to blend malicious content with benign-looking files. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://gimoguvi.ru/strik?utm_term=how+to+get+ice+hacks+on+surviv.io PDF link annotation
    • https://gabofulonu.weebly.com/uploads/1/3/4/7/134730366/180ab7bfd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453344/normal_5fe5475a46b25.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408176/normal_60689c96641c9.pdfIn PDF document text
    • https://gazezujebek.weebly.com/uploads/1/3/4/8/134881616/7843998.pdfIn PDF document text
    • https://defupaga.weebly.com/uploads/1/3/2/6/132681490/2114616.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480735/normal_604420c71e116.pdfIn PDF document text
    • https://murunabijijot.weebly.com/uploads/1/3/5/4/135401069/savafiribu.pdfIn PDF document text
    • https://rupuxiziwaxez.weebly.com/uploads/1/3/4/7/134765543/kozakuxumubu-risaganefo-xezemakaxejax.pdfIn 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://s3.amazonaws.com/pazatuv/bcdedit_set_useplatformclock_default.pdfIn PDF document text
    • https://s3.amazonaws.com/vixuwogetiv/face_beauty_camera_apk.pdfIn PDF document text
    • https://s3.amazonaws.com/tabobujimo/bottomsheetdialogfragment_rounded_corners.pdfIn PDF document text
    • https://s3.amazonaws.com/dowesitobuga/2013_jeep_grand_cherokee_overland_5.7_hemi_specs.pdfIn PDF document text
    • https://s3.amazonaws.com/jasadavebaga/51902812713.pdfIn PDF document text
    • https://s3.amazonaws.com/lijopavexanuse/xogomuzepifetuwamevovad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eec0a095-b67e-4b27-a4db-94ec9accca8c/what_engine_does_a_ford_ranger_have.pdfIn PDF document text
    • https://s3.amazonaws.com/risisipajole/how_a_cool_mist_humidifier_works.pdfIn PDF document text
    • https://s3.amazonaws.com/pipaneku/73293368051.pdfIn PDF document text
    • https://s3.amazonaws.com/tamovagag/insuficiencia_cardiaca_aguda_fisiopatologia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1c42f58e-f5de-4d9c-833d-6552a5e94b12/stock_market_hours_today_pst.pdfIn PDF document text
    • https://s3.amazonaws.com/somisilegex/29311955808.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_off0000e5da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5DA 5120 bytes
SHA-256: 6b8357d86d57bdfa5378761bf4f37935c177ec2bcd49d3c91771753f118825eb
font_01_sfnt_off0000f758.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF758 11924 bytes
SHA-256: 4ec51d2aa13fa81ab4bc82e2b3b1910ead82168ed280c97afd7347782bd88031
font_02_sfnt_off00011eb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB0 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3