Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8261a713896120b…

MALICIOUS

PDF

92.5 KB Created: 2021-03-14 23:05:14 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: c0343451b983bc7e934bfd528b630710 SHA-1: a62840b98b074e2002462e2951a1d35e2f37d564 SHA-256: f8261a713896120b674f27271fe5d423734c5eb626695812f9fef60ac04664b3
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external links to other PDFs hosted on disposable domains, which is a common tactic for SEO manipulation or distributing further malicious payloads. The presence of multiple external links and the use of disposable hosting suggest a phishing or content distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://vilenefex.ru/wix?keyword=how+full+is+your+bucket+book+pdf+download PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4458848/normal_602e6d0721675.pdfIn PDF document text
    • https://wedarudojov.weebly.com/uploads/1/3/4/0/134012757/3639812.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412780/normal_60324cdb7ec1f.pdfIn PDF document text
    • https://dewubolisevibe.weebly.com/uploads/1/3/4/3/134318954/36c25.pdfIn PDF document text
    • http://tulavesew.getenjoyment.net/doduxozuxafibusokovunatak.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458826/normal_5ff496923730f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368246/normal_5fd8659e35e16.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370059/normal_602f38e2a4d97.pdfIn PDF document text
    • https://tavadubamik.weebly.com/uploads/1/3/4/4/134473349/wibovetul_zibefiw.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4503050/normal_5ff9b524b5062.pdfIn PDF document text
    • https://jonipafatanepa.weebly.com/uploads/1/3/2/7/132741476/56f032b2f5.pdfIn PDF document text
    • https://xajijalati.weebly.com/uploads/1/3/3/9/133997138/zefevijajos-radikovutoroxik.pdfIn PDF document text
    • https://rekinijibir.weebly.com/uploads/1/3/2/3/132302710/dasogelejuviro.pdfIn PDF document text
    • http://ninomut.sportsontheweb.net/9047436704.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4469849/normal_600609d26b69e.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://uploads.strikinglycdn.com/files/9b73c385-25ab-4f14-9ec4-d46f877f65cc/wopetevimokekomuwos.pdfIn PDF document text
    • http://xidalagep.myartsonline.com/of_mice_and_men_chapter_1_audio.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e99a8c4-6de8-494f-966e-e32f6241d7db/tikex.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a6643309-a555-4f91-8995-817e9bf6d429/whirlpool_duet_steam_dryer_making_screeching_noise.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_off00011c43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C43 5388 bytes
SHA-256: 37c7debfcb2b9602715903046e0de3999e10b5f107add2aa005c3f448f501501
font_01_sfnt_off00012eb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EB0 12084 bytes
SHA-256: 7923afe0d5dde4c357ed8b6c506d59a81f9ca857e10405d7f357e6e93dd889fc
font_02_sfnt_off000156b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156B8 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361