Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a490f1ef9108ae0…

MALICIOUS

PDF

90.6 KB Created: 2021-03-18 10:40:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: cba413f81d61220a940c33410f45bdbc SHA-1: 9823bf6340fb3b79b5d47404cd9934297693be2e SHA-256: 4a490f1ef9108ae06bba3826d42c32b08ac38c66753388d43f92d0a3c16d20ab
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with one heuristic specifically identifying a 'PDF link farm' designed for SEO manipulation. The document body, though partially garbled, suggests a file conversion lure ('Chuy cn file pdf anh sang word'). The presence of embedded URLs and the ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the PDF structure itself is indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • 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.
  • 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://jacksth.ru/award?keyword=chuy%25E1%25BB%2583n+file+pdf+%25E1%25BA%25A3nh+sang+word PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4425913/normal_60121bf51605f.pdfIn PDF document text
    • https://tizusetupo.weebly.com/uploads/1/3/1/6/131607013/7707849.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373016/normal_5fd3cc0f6db70.pdfIn PDF document text
    • https://barijimuje.weebly.com/uploads/1/3/1/4/131406344/gevesuzipagudikaje.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4478146/normal_5fceae22e1946.pdfIn PDF document text
    • https://puwibovur.weebly.com/uploads/1/3/4/6/134639487/ddba8a819.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376600/normal_60348ad48428c.pdfIn PDF document text
    • https://godikifamubexi.weebly.com/uploads/1/3/4/6/134622632/2843968.pdfIn PDF document text
    • https://warodimaziwini.weebly.com/uploads/1/3/4/6/134611971/tetazerurer-soxekakome.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458631/normal_60386d7627f29.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/lorugipopuxe/excel_vba_vlookup_dynamic_sheet_name.pdfIn PDF document text
    • https://c4cd0dbc-23d7-4f11-b65f-2561cec8abe5.filesusr.com/ugd/516793_e87ec90916dd4423adf36f5350a55655.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/setaxilitozuko/aziz_ansari_news_reporter.pdfIn PDF document text
    • https://s3.amazonaws.com/divikufifir/canine_dental_chart.pdfIn PDF document text
    • https://4779f2f8-a33e-4327-9c78-21ee0bcf4620.filesusr.com/ugd/31bf02_020eab581420448689ffc98de5fd7a83.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/sirilagewuga/mensuration_2d_questions_and_answers.pdfIn PDF document text
    • https://f730d15c-1921-46d2-b6d4-288333e40990.filesusr.com/ugd/e2c223_49ac8aa219114aafb3733efaf4877fd4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/folexapurilowe/android_vs_ios_market_share_australia.pdfIn PDF document text
    • https://s3.amazonaws.com/zesotat/what_does_upward_means_in_english.pdfIn PDF document text
    • https://s3.amazonaws.com/pidufozu/15734253058.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/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
font_00_sfnt_off0000e44a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE44A 6568 bytes
SHA-256: 2ba6e0c4516ae528974428ab90d2fcb845e31fc6427c3681d976df34e50bf0fe
font_01_sfnt_off0000f497.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF497 5876 bytes
SHA-256: 1a62e5a0b2b4b1c375a852a65a1f50dd1dd2525980e40026d74cf79aa1e7add6
font_02_sfnt_off000107d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107D3 2468 bytes
SHA-256: bc9f2bf440da17a4b026119449c96cb916fc7cd5f1123f1e39606e6e33add231
font_03_sfnt_off000112e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E4 22700 bytes
SHA-256: 36256d18a5dcd4e30617006973ec79078e467f38773bd1875477c133f49ac1a6
font_04_sfnt_off00014563.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14563 16036 bytes
SHA-256: 9559dd1bd908241551916101fda3d445a26f5c4b506a1423f23393456f9d5940