Malicious PDF — malware analysis report

Static analysis result for SHA-256 a91b9e85f5777227…

MALICIOUS

PDF

85.9 KB Created: 2021-03-21 04:11:27 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: de58a9473ff50c28e54f158ea99873fe SHA-1: aaa101ba29ac192a9538bbc5890e5ddb5c9c9911 SHA-256: a91b9e85f57772276437323c8dacb82b363d91b9ddd97aa13418a292b303ae48
252 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links pointing to external PDF files, many hosted on disposable domains. This behavior is indicative of a link farm, likely used for SEO manipulation or to distribute malicious content. The presence of a known malicious redirector URL further supports this assessment. ClamAV detection and ML classification confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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 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.
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://crophysi.ru/wix?keyword=tv+guide+corpus+christi In PDF document text
    • https://lemarowaverixax.weebly.com/uploads/1/3/4/3/134371099/d026b2.pdfIn PDF document text
    • https://kukitame.weebly.com/uploads/1/3/1/3/131379641/jawuko-nulosozi.pdfIn PDF document text
    • https://federadedeladol.weebly.com/uploads/1/3/4/6/134626130/lumawetaravuk_vivinexoj.pdfIn PDF document text
    • https://kewegiru.weebly.com/uploads/1/3/1/4/131438086/5294218.pdfIn PDF document text
    • http://najetaxu.mygamesonline.org/60027954333.pdfIn PDF document text
    • https://pipomojum.weebly.com/uploads/1/3/4/4/134437532/welomi.pdfIn PDF document text
    • https://pitulero.weebly.com/uploads/1/3/2/6/132683003/fogapemezejubet.pdfIn PDF document text
    • https://gokatejasefe.weebly.com/uploads/1/3/4/6/134650338/nugunewomuje.pdfIn PDF document text
    • https://gabamavipe.weebly.com/uploads/1/3/3/9/133999819/838337.pdfIn PDF document text
    • http://sewakasatixori.medianewsonline.com/corporations_act_2020_full.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://44034db3-6cdd-4729-adf3-7ccd6afcf354.filesusr.com/ugd/9fe9cc_691202664bdb44baaaa4ab4657917661.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jawusawar/que_son_los_lipidos_y_como_se_clasifican.pdfIn PDF document text
    • https://fccd5518-64e1-462d-9dbe-8d8d8a19ca7a.filesusr.com/ugd/eb005d_e9fbcbdd27f44b828c55fcbd95410d14.pdf?index=trueIn PDF document text
    • https://181f3bdf-810f-4c34-abb3-9f3362228cd6.filesusr.com/ugd/30415f_b9e133d9120a4a3cae33c6f2d2df87f4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/varolexexus/tuwezolenovobujegixoju.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/65342009-78d2-462e-94fd-f2253dfc48b2/28685850887.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e7095b9f-e507-408d-af96-ce2b01cfd4d1/canon_mp160_ink_refill.pdfIn PDF document text
    • https://s3.amazonaws.com/tubupejevomo/salodepilopuviregare.pdfIn PDF document text
    • https://24d1f61b-f5c5-4d2f-8180-62589f44e8d8.filesusr.com/ugd/eed56f_d1a11b4a06144d2b93c0f4365b1b2cca.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a909bf3-30a0-42c6-a493-8d13e219815b/how_to_mix_oil_and_gas_for_stihl_leaf_blower.pdfIn PDF document text
    • https://s3.amazonaws.com/vavabi/cdrh_laser_product_annual_report.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/13f39e88-e86b-4b3b-8cbc-b112720dcb26/zudexizegima.pdfIn PDF document text
    • https://f6e2a16f-d004-42cd-8f17-0463e090774c.filesusr.com/ugd/c70c35_4bf07bfbb0224f80a6339251b96b06e6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/86eac293-ca74-4db7-bb5e-c735299cac7b/how_to_install_windows_7_from_usb_pen_drive_in_lenovo_laptop.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011103.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11103 5104 bytes
SHA-256: e0594d4aec4891d3d07aa1c24c3c445e01d747c53846ec1369b1dbdf75abd570
font_01_sfnt_off0001226a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1226A 12116 bytes
SHA-256: 8064745b6d8e7bb26335957e6a08c4a276461360deadc7e29c2e06191744cc12