Malicious PDF — malware analysis report

Static analysis result for SHA-256 5120d189c9945b75…

MALICIOUS

PDF

80.0 KB Created: 2021-09-09 10:47:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 20c3716adbf2a87c2f36414e307b4be4 SHA-1: 438f5d6e3cdc296304e33e56aa8b8630feab2794 SHA-256: 5120d189c9945b75bc3e70df2ca329e203e6a294a10fecaa86c3baa206aeac5b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous links, including one with a UTM term suggesting a lure for 'thumbnail maker pro apk download', points towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://krisoc.ru/uplcv?utm_term=thumbnail+maker+pro+apk+download PDF link annotation
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138215943463---zamolobudat.pdfIn PDF document text
    • http://poexali.org/static/image/_u/system/files/88687595106.pdfIn PDF document text
    • https://austdoorcaocap.com/upload/files/81245298316.pdfIn PDF document text
    • https://camping-du-lac-dijon.com/userfiles/fichiers/99009098737.pdfIn PDF document text
    • https://thic.muki001.com/plugin/ce1/ckfinder/userfiles/files/29461341119.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/60142563229.pdfIn PDF document text
    • http://csc-vietnam.vn/uploads/userfiles/file/30603001594.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16138095f68abb---bajagogozexazujumefax.pdfIn PDF document text
    • http://ilonew.tasksplan.com/ckfinder/userfiles/files/fizivubefagilubara.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210903_63D74F7BDA483224.pdfIn PDF document text
    • https://tennis-samara.ru/img/file/rudiw.pdfIn PDF document text
    • https://408of53crownstreet.com/assets/media/files/kukofapeliba.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/40838684060.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/satibagimilezaf.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/judixed.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/jegasuzaxadev.pdfIn PDF document text
    • http://bronia.org/userfiles/file/96169383329.pdfIn PDF document text
    • http://wonderful-foods.net/userfiles/file/77428184419.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16138bf70d8bcf---devefusiloxurusimovani.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/72395676674.pdfIn PDF document text
    • http://rucodelniza.ru/userfiles/file/44898336451.pdfIn PDF document text
    • https://mollis.rs/files/72475332873.pdfIn PDF document text
    • http://armiikrajowej36.pl/public/upload/ckfinder/userfiles/files/30936632219.pdfIn PDF document text
    • http://fullx.net/files/28044046524.pdfIn PDF document text
    • https://willmarareachamber.com/ckfinder/userfiles/files/vavetupubij.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD665 16848 bytes
SHA-256: 996e6da9c3bb62184fe559ba5436859c82bf4b894a1ef2bd920375da1d8af102
font_01_sfnt_off000101fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FB 10772 bytes
SHA-256: e95c788ec75b7b193dac43cda670b27ec8067d01e522fb6a4d71c4fedb622ff0
font_02_sfnt_off00011a43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1