Malicious PDF — malware analysis report

Static analysis result for SHA-256 28706c9a3008162d…

MALICIOUS

PDF

79.4 KB Created: 2021-03-04 18:48:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: bb57747b1924eed2a329b1dd62af1236 SHA-1: afd00fe6d8724d6ae48664297356fdbc7c54df01 SHA-256: 28706c9a3008162d1ac8d8521700373db41aed34b8401d77c3d8445f36a055f7
156 Risk Score

Malware Insights

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

The PDF contains a high number of external links, many pointing to S3 buckets and other domains, indicative of a link farm or SEO manipulation. One critical heuristic identified a mass external PDF link farm. The ML classifier and ClamAV also flagged this PDF as malicious, specifically as a phishing trojan. While no scripts were extracted, the PDF structure and numerous external links suggest an attempt to redirect users to potentially malicious or SEO-abused content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • 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://zajinet.ru/award?keyword=of+more+than+average+height+synonym PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4414152/normal_5ffc207dd45c1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426571/normal_603165df90f7f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485930/normal_603f82a28f54a.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/mijumomub/6485252177.pdfIn PDF document text
    • https://86146b48-cf95-488a-b5a0-22832f4589a6.filesusr.com/ugd/3b4eee_ef37da6ed9224794a2f7c064c04cc1e4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zunaporam/how_to_pair_polk_soundbar_with_iphone.pdfIn PDF document text
    • https://s3.amazonaws.com/kegubinefuda/rcog_guidelines_for_cardiac_disease_in_pregnancy.pdfIn PDF document text
    • https://s3.amazonaws.com/mizeteb/bass_booster_for_android.pdfIn PDF document text
    • https://s3.amazonaws.com/womirofop/3148463433.pdfIn PDF document text
    • https://s3.amazonaws.com/zuwosil/mathematics_dictionary_james.pdfIn PDF document text
    • https://s3.amazonaws.com/napejaxosinages/jatexuzik.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f2afce23-2380-4eeb-8d8c-cd05f7c11fe9/wajikezeke.pdfIn PDF document text
    • https://s3.amazonaws.com/wokesabisevo/how_to_clean_crane_ultrasonic_cool_mist_drop_shape_humidifier.pdfIn PDF document text
    • https://s3.amazonaws.com/vuxalirudidel/asphalt_8_transfer_from_android_to_ios.pdfIn PDF document text
    • https://92fa68c6-d088-48c5-94d9-776fe0504fc0.filesusr.com/ugd/5a053b_5e9b87817f5b49fea5e963b00da3fa63.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8db9507-c582-4545-af6b-230130de9a21/41127297373.pdfIn PDF document text
    • https://s3.amazonaws.com/zalomi/caples_lake_ice_fishing_report.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a1372cf1-6223-46c9-a419-8314dc14964c/47984278980.pdfIn PDF document text
    • https://s3.amazonaws.com/mipeboro/kavobugerorarevuro.pdfIn PDF document text
    • https://59cf682b-6680-4a08-8b8d-0472bab64ef7.filesusr.com/ugd/d7d6cd_eb51ded987954aa28a6232f7396fcd40.pdf?index=trueIn PDF document text
    • https://944456f3-75eb-4cd6-bbfd-656b3713ada1.filesusr.com/ugd/2c8d66_a99cd6f3c80a46da83f73746ee246be1.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/86317001-e5a2-4c90-a517-e65c311edacd/doctor_sleep_movie_on_netflix.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_off0000fac4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAC4 5336 bytes
SHA-256: 01b6ae81687a189f0aab10a802cead65116fd4c8c26690d1fa87818d49599084
font_01_sfnt_off00010ccf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CCF 10192 bytes
SHA-256: ce64875c0137cce532bcb8b758ab0bd44d10283e97a4a65fa4b74c58cd524613