Malicious PDF — malware analysis report

Static analysis result for SHA-256 985c9ba88a340345…

MALICIOUS

PDF

80.9 KB Created: 2021-09-13 15:42:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6bc506b0ccfa5711d5ae67944ea9c431 SHA-1: 8a11932b43d383eadf5faf8888695f887b8f6521 SHA-256: 985c9ba88a340345643ee65aa42422811538b6d67c73f66f100c90faa8a2d0d4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs, with one specifically pointing to a suspicious domain 'allytemp.ru' that is likely used for phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is part of a link farm hosted on disposable domains, further suggesting malicious intent. The ML classifier and ClamAV detection strongly indicate this PDF is malicious, likely serving as a lure to download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 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://allytemp.ru/uplcv?utm_term=game+keyboard+ios+gta+san+andreas PDF link annotation
    • http://www.casasemio.com.br/ckfinder/userfiles/files/dupefozaneluzaxodo.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613df994c3e4b---70218211788.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/11377892832.pdfIn PDF document text
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/28009810602.pdfIn PDF document text
    • http://bangdientunhk.com/upload/files/mubibanifo.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210904_075054.pdfIn PDF document text
    • http://wami.cc/data/files/32383803480.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/lekekonixevefagivobavazem.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613a07f04c110---tusanazosulezaganika.pdfIn PDF document text
    • https://terracetemayonetim.com/upload/ckfinder/files/ferige.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1613db838d9b0c---89431510929.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3532a70d5---28933483797.pdfIn PDF document text
    • http://ya-ke.cn/admin/upload/laguwekagef.pdfIn PDF document text
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/21089756143.pdfIn PDF document text
    • http://www.ruben.pl/ckfinder/userfiles/files/7387735166.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/dakaxajenavenumuk.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/navebelidijujaravobodutu.pdfIn PDF document text
    • https://hunghiephuylog.com/upload/files/pijezaxax.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/rejitesoxorugagogos.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/35938536021.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-5/20210905141953710153.pdfIn PDF document text
    • https://alummaswaja.com/yii/sdbalikpapan/home/images/upload/files/26198839755.pdfIn PDF document text
    • http://dd-eng.com/files/files/vugivafetuz.pdfIn PDF document text
    • http://neoclassicalmansions.com/uplds/file/78251838304.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_off0000d831.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD831 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f043.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF043 17184 bytes
SHA-256: b9364dda8f0b10932facb5443382dba346c1c7ba70fa068af0d22d560a4ac9e6
font_02_sfnt_off00011cbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CBE 10928 bytes
SHA-256: 4d21251d0bf1171a5dca43ff490f378bc032ca8c785fe74667ca7dfcd98c699b