Malicious PDF — malware analysis report

Static analysis result for SHA-256 21a87b7e8c4eb4e7…

MALICIOUS

PDF

88.1 KB Created: 2021-08-02 04:25:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d585d9956f9754dac6fee2d85730413f SHA-1: 86929796270028a343125b81a8eb9733eebacbc2 SHA-256: 21a87b7e8c4eb4e75d2cda981de7a45ea76993dbd88f5436919bbc1037c46235
204 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including a link farm on disposable hosting and a compromised CMS upload link. The presence of a visual download button lure and password instructions for an archive strongly suggests a phishing or malware delivery attempt. ClamAV also detected this file as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://khanaphatgroup.com/UserFiles/file/17107063523.pdf
    • https://efnnma.org/files/file/nefiturufi.pdf
    • https://rijst.nu/userfiles/file/finozojob.pdf
    • https://hiroyoung.com/data/files/jenimavakiraxewafawa.pdf
    • https://samuelben-horin.com/userfiles/file/65917909603.pdf
    • http://deltastal.ru/userfiles/file/kupip.pdf
    • https://ancoraeducacion.com/images/nezuxepolofi.pdf
    • http://baloneacessorios.com/_upload/file///kasuwowesijalinovod.pdf
    • http://innotack.com/userfiles/files/45369821343.pdf
    • http://dent-pro.cz/pic/file/vikefumepigelalepijiwukoz.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbeb3df972---nowabesepisavibodaxojos.pdf
    • https://homecareangels.ca/files/files/files/52479745708.pdf
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/c9b0eb48f99266646988cf6e9f57bb42/88501483278.pdf
    • http://top-conversion.ru/ckfinder/userfiles/files/sizemaj.pdf
    • https://restavracia02.com/userfiles/file/87301943814.pdf
    • https://patriciobanados.cl/upload/file/
    • http://cuacuonnhaxuongbinhduong.com/upload/files/sokugajudaxesijexugibe.pdf
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/9t9digfqavsecvag4pmcbis168/vewudagabexutodape.pdf
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/toimitb9683ait5luf2l19d52q/88784695871.pdf
    • http://ttlh.vn/storage/ckfinder/files/3441641756.pdf
    • https://cooperspick.com/files/nuwatogavedavi.pdf
    • http://myucpb.net/userfiles/file/55161063457.pdf
    • http://wchs65.org/clients/b/bb/bb65574a37642f7fe3135935df861e67/File/gigogedonupabupuka.pdf
    • https://taipeitccia.org/CKEdit/upload/files/wokibewaduwomapeduxip.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=naruto+ultimate+ninja+storm+3+apk+android
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea14.bin
917c43d6162fe4415041be1e0d076aede95f0c20961f65668df81e9e9fd08a75
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA14 1736 bytes
font_01_sfnt_off0000f24e.bin
42bf93d4f4ae97a0555dba4887e19f9ba865ddcaaa1e45d6d6cdf4f023e464da
pdf-font-stream PDF embedded font (sfnt) at offset 0xF24E 17844 bytes
font_02_sfnt_off00012071.bin
f5d8747fdd54c959e7ea6e0e332914bb7d6838821c9dc90e89025e18ebbba4b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12071 11024 bytes
font_03_sfnt_off00013a13.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A13 16792 bytes