Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b73c5efd3229739…

MALICIOUS

PDF

86.0 KB Created: 2021-07-15 21:19:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 393a27445d27996c55e35792e8781326 SHA-1: a9826f16b5b1f08b6f2d4a60ab620419ec72635d SHA-256: 6b73c5efd3229739246268a2c3672c9793bb2adce7dd484b4c0f665c863d44a1
196 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 file contains numerous links, many pointing to compromised WordPress installations and disposable domains, which likely serve as a link farm to distribute further malicious content. The primary attack pattern observed is the use of these links to lure users into downloading additional malicious files, such as other PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160871235265c1---gupewibedawimewigim.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/6qsqpkmh490ebdo67f10e2iv6u/risagasogix.pdf
    • https://derfo.info/resimler/files/gevupuditozivaxafezuj.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/91df1a0225b9ce3dc51484028d1c2f55/16230831179.pdf
    • http://15449010.com/FileData/ckfinder/files/20210620_FC8E5939E23550F8.pdf
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/rrtla1ot79a4td7cbeeie6s76n/25019886495.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/a5837cd7b5bfd784bf0585f732147fae/geduvonimuwup.pdf
    • http://casaalu.com/luutru/files/11708959117.pdf
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/5ce4b420f61a9275db13d55c31d514a6/66321507472.pdf
    • https://trimix.bg/UserFiles/File/45910345301.pdf
    • https://cornerstonelaw.eu/userfiles//file/51561944694.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607df7f6b9dd2---xepewivavawukan.pdf
    • http://aihyang.com/userfiles/file/40810113519.pdf
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/sugajalazo.pdf
    • http://megaprestige.ru/uploads/files/xivukidakibedino.pdf
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/7e6a4cfd3466bf7abfd3ed6ce7701fcc/wukegomeren.pdf
    • http://for284.org/clients/7/74/7452b259410349f427184d5eaa48bde7/File/87990692985.pdf
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c81b960aa4---80211485183.pdf
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/hfljhf7167f0fokr4pl10onmq6/limelenasav.pdf
    • http://suapaiatuipelehakefamily.com/clients/80707/File/11441047349.pdf
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/aun88jvs1gpbn83dotecjaeeti/dewefomarivivibuzati.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f16ecce70---sologa.pdf
    • http://developmentassociationofnagaland.org/nbloom/fckuploads/file/81611148399.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=waterford+place+apartments
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed3a.bin
cc02f4941a57415599d5a1fbd7bbab9e62c311f40d6284abddc1bbc49b8d9080
pdf-font-stream PDF embedded font (sfnt) at offset 0xED3A 17320 bytes
font_01_sfnt_off00011a48.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A48 16792 bytes
font_02_sfnt_off0001325f.bin
bd9c719d9c73094618775e85af4a8d48e39633dc961cfd314374abe3f3049a81
pdf-font-stream PDF embedded font (sfnt) at offset 0x1325F 10684 bytes