Malicious PDF — malware analysis report

Static analysis result for SHA-256 7556fc778a4468ff…

MALICIOUS

PDF

78.6 KB Created: 2021-09-17 21:58:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: ad01855750ca70bb002dcd5a2f17ccb1 SHA-1: 3d07a46c3c764a13caf201adbac0243f1d511dac SHA-256: 7556fc778a4468ff3e25443a31672558161cab555f85453ec19458c85a5c8c7d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, many pointing to disposable hosting, suggesting it functions as a link farm. While no scripts were explicitly extracted, the PDF structure and numerous URLs strongly suggest an attempt to redirect users to malicious sites, likely for phishing or malware distribution, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9931

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 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://cructi.ru/uplcv?utm_term=master+pe+apk PDF link annotation
    • https://arerp.kr/data/file///kinuwufojujubisek.pdfIn PDF document text
    • http://pereplanirovkaoblast.ru/pict/file/56405428454.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/7165152737.pdfIn PDF document text
    • http://nuitsdartistes.eu/images/file/libojetupujero.pdfIn PDF document text
    • http://eikenhorstgroep.nl/userfiles/file/61376981696.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130dff92c7e7---30425237654.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/25860197912.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/45756836868.pdfIn PDF document text
    • http://ihdbd.org/upload/files/11879275228.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/pofagiwavovemomuzitutidoz.pdfIn PDF document text
    • http://robvancampen.nl/userfiles/file/sojigamigafuve.pdfIn PDF document text
    • http://gazomotor.com/allinone/file/vilusulu.pdfIn PDF document text
    • http://farmina.ru/uploads/files/ruxadupapaxavezuja.pdfIn PDF document text
    • https://zilalcooling.com/other_files/File/metonidaf.pdfIn PDF document text
    • http://jiangsutravel.kr/userfiles/files/20210907_203426.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/97538207937.pdfIn PDF document text
    • http://nepalbestcargo.com/userfiles/file/90625122624.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021090516450173499.pdfIn PDF document text
    • https://associazionemusicaviva.it/uploads/file/xovuf.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/dilif.pdfIn PDF document text
    • http://sushi-belovo.ru/files/45116174299.pdfIn PDF document text
    • http://eluvial.com/sites/all/sites/eluvial.com/files/lesixupasebesegotipejot.pdfIn PDF document text
    • https://aluvioneschicamocha.sinecsas.com/ckfinder/userfiles/files/kajusozesokotuto.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/nasujopavipatogeribijupir.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://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_off0000b381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB381 9968 bytes
SHA-256: 29c0cd524364e901b7ace2131e879f11f2aa05df787def503802e7f6457b4a9d
font_01_sfnt_off0000c9c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e1d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D4 1820 bytes
SHA-256: ef4c56b83544acc0eae329b123dcb13384a4443b8ee25b6b011fcec9f25c534c
font_03_sfnt_off0000ea59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA59 16160 bytes
SHA-256: fa5cbea137587b1d4bb1c548ff3f8d17a18587fe273de630a8d80f12e69f99e4
font_04_sfnt_off0000fff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF0 17224 bytes
SHA-256: e212e285d72175189f27d562af1e591c7a3a3f8cb8cbc6b2f667efbf64824946